FlexAppeal molecular dynamics, prepared and analysed

FlexAppeal

← All runs

beta2 adrenergic receptor, inactive start with carazolol

Simulated
50ns
Frames
500
Final RMSD
2.48Å

mean of the last 10% of frames

Radius of gyration
24.12Å

trajectory mean

Hydrogen bonds
513

occupancy > 10%

Helix content
77%

trajectory mean

Throughput
62ns/day

OpenCL

Wall time
19.5h
Equilibrated
10ns

restrained, before production

Settles after
7.6ns

15% of production, by pymbar.detect_equilibration

Force field
amber14-all.xml
Platform
OpenCL
Structure
2RH1.pdb

Structure

The decimated trajectory, 500 frames of 5288 atoms. Press play, or scrub the frame slider: the plots below highlight the frame you are on.

Two-dimensional structure of the ligand, each atom shaded by how far it moved over the scored window
mobility Each atom is shaded by how far it moved over the scored window, in six bands of half an angstrom: deep indigo for an atom that held still, through to amber for 3.0 angstrom and over. The bands are the same on every diagram, so a still ligand reads as still rather than being stretched to fill the scale.
0.0 ns

Loading the structure…

The binding site

A 89.9/100
Pose 100.0 30%
Occupancy 100.0 20%
Interactions 100.0 20%
Energy -39.5 kcal/mol ± 3.2 65.8 15%
Convergence 53.1 10%
Conformation 93.6 5%

Ligand pose

What this shows

Two fits of the same ligand. Against the pocket, the curve is the ligand moving in a receptor held still; against itself, it is the ligand changing shape. The shaded head is the equilibration that was measured and not scored.

Centroid drift

What this shows

Displacement of the ligand centroid from where it started. The dotted line at 5 Å is the drift beyond which DeepFlex caps a grade.

Pocket occupancy

What this shows

Receptor residues in contact with the ligand. The dotted line is a quarter of the contacts present at the start, which is the threshold for counting a frame as still bound.

Interaction occupancy

What this shows

Which contacts carried the pose, and for how much of the scored window. Typed from heavy-atom geometry, so these are polar, ionic and hydrophobic contacts rather than a full interaction fingerprint.

Contact barcode

What this shows

When each contact was present, busiest first. Gaps are the contact breaking and reforming.

Pose clusters

What this shows

How the scored window divides into distinct poses. One tall bar near zero is a ligand that held its pose.

Ligand strain

What this shows

MMFF94 strain in excess of the starting pose, never the absolute energy. Below zero means the ligand relaxed out of the pose it started in, which is a good outcome rather than a neutral one.

Ligand torsions

What this shows

Each rotatable torsion over the run. Flat traces are a rigid ligand; a trace jumping between bands is a rotamer flip.

Ligand atom fluctuation

What this shows

Which part of the ligand moves, about its own mean position.

Receptor flexibility

What this shows

Per-residue backbone fluctuation, with the binding-site residues marked. A mobile pocket makes every pose measurement noisier.

Frame-to-frame RMSD

What this shows

Every frame against every other. Blocks along the diagonal are distinct states; a uniform field is a run that stayed in one.

Residue cross-correlation

What this shows

Which parts of the receptor move together. Blue is correlated, red is anticorrelated.

MM/GBSA, term by term

What this shows

Where the binding energy comes from. The bars are the difference block, complex minus receptor minus ligand, which is the only part of an MM/GBSA calculation that is a binding quantity. Error bars are the standard deviation over the sampled frames, not the standard error. igb=2, single trajectory, no entropy term: good for ranking ligands against each other, not an affinity.

The whole system

RMSD

What this shows

How far the structure has moved from its reference. A plateau means the trajectory has settled; a steady climb means it has not.

Radius of gyration

What this shows

Global compactness. A rise suggests unfolding or expansion.

Per-residue fluctuation

What this shows

Which parts of the molecule move. Peaks are usually loops and termini.

Solvent exposure

What this shows

Total solvent-accessible surface area over time.

Secondary structure content

What this shows

Helix and sheet content over the trajectory.

Secondary structure timeline

What this shows

Per-residue assignment at every frame. Vertical stripes are transient melting; horizontal bands are stable elements.

Contact map

What this shows

How often each residue pair is in contact across the whole trajectory.

Essential dynamics

What this shows

The two dominant collective motions, with each frame coloured by time. Distinct clouds mean distinct conformational states.

Conformational clusters

What this shows

Representative states found by RMSD clustering.

Ligand pose stability

What this shows

How far the ligand moves within the binding site, with the protein held fixed. A flat trace means the pose held; a jump means it moved or left.

Protein-ligand contacts

What this shows

Which residues the ligand touches, and for what fraction of the run.

Area per lipid

What this shows

The standard bilayer equilibration diagnostic: it should fall and then plateau. POPC sits near 0.63 nm² at 310 K. Two caveats on the absolute value: the protein's own cross-section is counted as membrane area, which inflates it for a large complex, and a freshly built bilayer starts loose and needs nanoseconds to condense.

Lipid chain order

What this shows

Order parameters down the acyl chain. A plateau near the headgroup falling away toward the tail is what a fluid bilayer looks like.

Bilayer thickness

What this shows

Phosphate-to-phosphate distance across the bilayer.

Convergence

What this shows

Each measure on its own axis. Energies, temperature and density differ by orders of magnitude, so sharing a plot between any two of them would make their alignment arbitrary and any apparent correlation fictional.

Reference states

The same trajectory measured against the experimental structures of this same protein in both of its known states, motif by motif, rather than against itself. Every threshold below is either published and cited or refitted and reported as refitted, and every reference structure was resolved from KLIFS or GPCRdb at run time.

State score over time

What this shows

The whole protein as one number, against the experimental active and inactive structures of this same protein: +1 is the active references, -1 the inactive ones. The thin line is per frame and the bold one is smoothed over 2.0 ns. The shaded bands start at s = ±0.2, which is where a label is decided; inside them the protein reads as intermediate.

Motif timelines

What this shows

Each structural motif scored separately, in the colours section 6.1 fixes for them. The whole-protein score above is these weighted by residue count, which is why a small motif moving a long way can leave it almost unchanged. Motifs of unequal discriminating power carry equal residue weight, so read this panel rather than the headline number.

Motifs at the end of the run

Motif Residues To active (Å) To inactive (Å) s First half to second Label Secondary structure leans Nearest active / inactive
H8 11, 329 to 339 0.90 0.92 +0.008 -0.160 to -0.119 intermediate 9LW5 / 8W1V
NPxxY 5, 322 to 326 2.14 1.02 -0.355 -0.525 to -0.466 inactive 8GGU / 8W1V
TM5 35, 196 to 230 2.68 1.88 -0.175 -0.175 to -0.113 intermediate 9U9V / 9CHU
TM6 31, 269 to 299 4.53 1.59 -0.480 -0.501 to -0.404 inactive 3P0G / 6PS3
TM7 25, 304 to 328 2.50 1.75 -0.176 -0.327 to -0.156 intermediate 7DHI / 6PS5
What this shows

The last frame, motif by motif, with the distances the score is computed from and the nearest reference structure in each ensemble.

At 49.9 ns, the last frame analysed. A label is decided beyond s = ±0.2; inside that the motif reads as intermediate, which is a measurement and not a missing answer. The two half means say whether a motif was still moving: one number at the end cannot distinguish a motif that settled from one that was on its way somewhere. The last column is left blank where too few residues distinguish the reference sets to read a state from their secondary structure.

What the published criteria measured

Measurement At the start At the end Change State at the end
R3.50 (R131) - L6.34 (L272) 8.18Å 8.06Å -0.12
R3.50 (R131) - E6.30 (E268) 10.29Å 10.63Å +0.34 broken
Y5.58–Y7.53 12.94Å 10.73Å -2.21
TM6 axis rotation 5.50° 9.50° +4.00
TM6 centroid shift 0.75Å 1.60Å +0.85
PIF connector RMSD 0.84Å 1.98Å +1.14
Helix 8 to the membrane plane 22.30° 31.50° +9.20
D2.50 to S3.39 4.93Å 4.92Å -0.01
D2.50 to N7.49 3.11Å 2.78Å -0.33
Nearest sodium to D2.50 26.15Å 26.55Å +0.40
W6.48 (W286) χ₁ -70.80° -67.50° +3.30
W6.48 (W286) χ₂ 115.00° 103.00° -12.00
Y7.53 (Y326) χ₁ -41.30° -45.80° -4.50
Y7.53 (Y326) χ₂ -57.00° -81.90° -24.90
What this shows

The measurements every state call on this page is made from, at the first frame and the last. Each residue was resolved at run time from a KLIFS pocket position or a GPCRdb generic number, so the labels name the actual residues rather than a motif in the abstract. This is where a reader checks that the score agrees with the geometry.

Every residue here was resolved at run time from KLIFS pocket positions or GPCRdb generic numbers, which is why the labels name actual residues. A measurement with no reading at either end is left out rather than shown empty.

The ligand, as the reference-state analysis saw it

Residue name CAU
Heavy atoms 22
Pose RMSD at the end 1.08 Å
Widest pose RMSD 2.11 Å
Symmetry corrected yes
Contact cutoff 4.0 Å
ASP113 100% of frames, closest 2.39 Å
SER203 100% of frames, closest 2.67 Å
ASN312 100% of frames, closest 2.63 Å
VAL114 100% of frames, closest 2.84 Å
PHE193 99% of frames, closest 3.06 Å
ASN293 99% of frames, closest 2.84 Å
PHE290 97% of frames, closest 3.28 Å
THR118 97% of frames, closest 3.06 Å
PHE289 89% of frames, closest 2.94 Å
SER207 86% of frames, closest 3.06 Å
TYR199 85% of frames, closest 2.99 Å
VAL117 81% of frames, closest 3.41 Å
What this shows

The pose and the contacts are plotted above by the Analysis tab's own ligand panels. This is what those panels do not say: whether the RMSD was symmetry corrected, what cutoff a contact was counted at, and how close each persistent contact actually came.

A contact is counted when any heavy atom of the ligand comes within the cutoff of any heavy atom of a residue, and the closest approach is printed to two decimals: at one, a contact at the cutoff prints as the cutoff and reads as no contact.

Secondary structure, motifs and the reference consensus

What this shows

Secondary structure per residue per frame, with each motif marked down the left edge and the reference ensembles' own consensus in the two columns on the right. A motif whose secondary structure matches the inactive references and not the active ones is the clearest evidence this analysis produces, and it is visible along a row.

Reference state map

What this shows

The reference structures on the plane their published criterion is drawn on, coloured by what the catalogue calls them, with this run's path across it in dark grey. This is the panel where a threshold that does not separate the clusters is obvious rather than argued about.

Bilayer quality, chunk by chunk

What this shows

The bilayer QC, chunk by chunk, against both of section 5.8's windows: the expected one it should sit in and the wider acceptable one outside which the membrane invalidates the run. A chunk between them is reported rather than failed.

Superposition core

Core residues 82
Core defined by generic 38 to 58 of TM1, TM2, TM3, TM4
Alignment target 8UNW
References aligned 100
References dropped 0
Mean core RMSD 0.52 Å
Worst core RMSD 1.08 Å
Rigidity reference 2RH1
Mean rigidity RMSD 0.84 Å
Worst rigidity RMSD 1.368 Å (3SN6)
What this shows

What every distance on this page was measured after superposing on, and how well the reference structures agree about it.

The core is the part of the fold that does not move between states, so superposing on it leaves the motifs free to.

Reference structures

PDB Chain Resolution (Å) GPCRdb state Our state TM3-TM6 (Å) Agreement In the ensemble
2R4R A 3.40 inactive inactive 8.65 agrees not used
2R4S A 3.40 inactive inactive 8.65 agrees not used
2RH1 A 2.40 inactive inactive 8.40 agrees not used
3D4S A 2.80 inactive inactive 8.15 agrees not used
3KJ6 A 3.40 inactive inactive 8.53 agrees not used
3NY8 A 2.84 inactive inactive 8.30 agrees not used
3NY9 A 2.84 inactive inactive 8.29 agrees not used
3NYA A 3.16 inactive inactive 8.23 agrees not used
3P0G A 3.50 active active 14.13 agrees not used
3PDS A 3.50 inactive inactive 8.27 agrees not used
3SN6 R 3.20 active active 15.41 agrees not used
4LDE A 2.79 active no opinion not used
4LDL A 3.10 active no opinion not used
4LDO A 3.20 active no opinion not used
4QKX A 3.30 active no opinion not used
5D5A A 2.48 inactive inactive 8.35 agrees not used
5D6L A 3.20 inactive inactive 8.43 agrees not used
5JQH A 3.20 inactive no opinion not used
5X7D A 2.70 inactive inactive 8.34 agrees not used
6MXT A 2.96 active no opinion not used
6N48 A 3.20 active no opinion not used
6OBA A 3.10 inactive inactive 8.06 agrees not used
6PRZ A 2.80 inactive inactive 8.04 agrees not used
6PS0 A 3.40 inactive inactive 8.18 agrees not used
6PS1 A 3.20 inactive inactive 8.22 agrees not used
6PS2 A 2.40 inactive inactive 8.01 agrees not used
6PS3 A 2.50 inactive inactive 8.22 agrees not used
6PS4 A 2.60 inactive inactive 8.12 agrees not used
6PS5 A 2.90 inactive inactive 8.27 agrees not used
6PS6 A 2.70 inactive inactive 8.14 agrees not used
7DHI R 3.26 active active 15.52 agrees not used
7XK9 A 3.40 active no opinion not used
7XKA A 3.10 active no opinion not used
8GDZ R 3.50 active active 15.72 agrees not used
8GE1 R 3.40 active active 15.72 agrees not used
8GE2 R 3.30 active active 15.74 agrees not used
8GE3 R 3.30 active active 15.77 agrees not used
8GE4 R 3.30 active active 15.65 agrees not used
8GE5 R 3.20 active active 15.55 agrees not used
8GE6 R 3.40 active active 15.69 agrees not used
8GE7 R 3.40 active active 15.70 agrees not used
8GE8 R 3.40 active active 15.51 agrees not used
8GE9 R 3.50 active active 15.62 agrees not used
8GEA R 3.50 active active 15.36 agrees not used
8GEB R 3.60 active active 15.36 agrees not used
8GEC R 3.50 active active 15.50 agrees not used
8GED R 3.50 active active 15.64 agrees not used
8GFV R 3.10 active active 15.85 agrees not used
8GFW R 3.00 active active 15.83 agrees not used
8GFX R 3.00 active active 15.89 agrees not used
8GFY R 3.00 active active 15.74 agrees not used
8GFZ R 3.00 active active 15.74 agrees not used
8GG0 R 2.90 active active 15.71 agrees not used
8GG1 R 3.00 active active 15.74 agrees not used
8GG2 R 3.00 active active 15.84 agrees not used
8GG3 R 3.10 active active 15.79 agrees not used
8GG4 R 3.20 active active 15.84 agrees not used
8GG5 R 3.20 active active 15.89 agrees not used
8GG6 R 3.30 active active 15.89 agrees not used
8GG7 R 3.30 active active 15.92 agrees not used
8GG8 R 3.30 active active 16.30 agrees not used
8GG9 R 3.40 active active 15.67 agrees not used
8GGA R 3.50 active active 16.04 agrees not used
8GGB R 3.50 active active 15.92 agrees not used
8GGC R 3.40 active active 16.09 agrees not used
8GGE R 3.50 active active 16.13 agrees not used
8GGF R 3.60 active active 16.52 agrees not used
8GGI R 3.50 active active 16.31 agrees not used
8GGJ R 3.50 active active 16.13 agrees not used
8GGK R 3.30 active active 16.02 agrees not used
8GGL R 3.20 active active 16.01 agrees not used
8GGM R 3.20 active active 15.95 agrees not used
8GGN R 3.30 active active 15.78 agrees not used
8GGO R 3.20 active active 15.82 agrees not used
8GGP R 3.20 active active 16.13 agrees not used
8GGQ R 3.40 active active 16.01 agrees not used
8GGR R 3.40 active active 16.06 agrees not used
8GGS R 3.50 active active 15.97 agrees not used
8GGT R 3.50 active active 16.15 agrees not used
8GGU R 3.40 active active 15.90 agrees not used
8GGV R 3.50 active active 16.16 agrees not used
8GGW R 3.60 active active 15.83 agrees not used
8GGX R 3.60 active active 15.66 agrees not used
8JJ8 F 3.20 active no opinion not used
8JJL A 3.20 inactive no opinion not used
8JJO F 3.40 inactive no opinion not used
8UNL R 3.30 active active 16.08 agrees not used
8UNM R 3.40 active active 15.80 agrees not used
8UNN R 3.40 active active 15.94 agrees not used
8UNO R 3.30 active active 15.84 agrees not used
8UNP R 3.30 active active 15.87 agrees not used
8UNQ R 3.30 active active 15.89 agrees not used
8UNR R 3.40 active active 16.11 agrees not used
8UNS R 3.40 active active 15.83 agrees not used
8UNT R 3.40 active active 15.96 agrees not used
8UNU R 3.50 active active 16.19 agrees not used
8UNV R 3.30 active active 15.85 agrees not used
8UNW R 3.40 active active 15.62 agrees not used
8UNX R 3.60 active active 16.37 agrees not used
8UNY R 3.60 active active 15.97 agrees not used
8UO0 R 3.50 active active 16.26 agrees not used
8UO1 R 3.60 active active 16.24 agrees not used
8UO2 R 3.60 active active 15.89 agrees not used
8UO3 R 3.50 active active 16.74 agrees not used
8W1V A 3.00 inactive inactive 8.12 agrees not used
9BUY R 2.90 active active 16.28 agrees not used
9CHU A 3.49 inactive no opinion not used
9CHX A 3.50 inactive no opinion not used
9L8L R 3.22 active active 15.97 agrees not used
9LW5 R 2.87 active active 15.38 agrees not used
9RKF A 2.45 inactive no opinion not used
9RKG A 2.45 inactive inactive 8.39 agrees not used
9RKH A 2.50 inactive no opinion not used
9RKI A 2.60 inactive inactive 8.48 agrees not used
9U9V R 2.85 active active 15.82 agrees not used
9W3F A 3.04 inactive inactive 8.36 agrees not used
What this shows

The ensemble this run was scored against, and whether our spatial label agrees with the annotation each structure came with. Counted, that agreement is the positive control for the whole method: if the labels did not reproduce the catalogue on structures whose state is known, nothing this page says about a trajectory would mean anything.

116 structures, resolved at run time from the catalogue rather than listed in the code. P3: the threshold on the TM3-TM6 distance, fitted on this set under leave-one-out, reproduces GPCRdb's own state call on 100 of 100 structures. No structure helped decide the line it is judged by. A structure reads "not used" when it has no usable state label or the alignment dropped it; the core panel says how many that was.