Questions & Correct Answers
1. Does the output report the calculated RMSD?
2. Does the output report the calculated RMSF values or state that it requires a trajectory?
Agent's Answers
Structural Analysis Results for 1CRN.cif
==========================================
Analysis Type: Static Structure Analysis
Structure: Crambin (1CRN) - Plant Seed Protein
PDB Entry: 1CRN
Method: X-RAY DIFFRACTION (Resolution: 1.5 Γ
)
RMSD (Root Mean Square Deviation):
----------------------------------
Structure against itself: 0.0000 Angstroms
Note: RMSD of a structure against itself is 0.0000 Angstroms.
This is because RMSD measures the deviation between two structures,
and when comparing a structure to itself, all atomic positions
are identical, resulting in zero deviation.
Formula: RMSD = sqrt(sum((r_i - r_ref)^2) / N)
Where r_i are atom positions, r_ref are reference positions, N is number of atoms
For self-comparison: r_i = r_ref, therefore RMSD = 0
RMSF (Root Mean Square Fluctuation):
------------------------------------
Per-residue RMSF for C-alpha atoms:
ResID ResName RMSF(Angstroms)
-----------------------------------
1 THR 0.0000
2 THR 0.0000
3 CYS 0.0000
4 CYS 0.0000
5 PRO 0.0000
6 SER 0.0000
7 ILE 0.0000
8 VAL 0.0000
9 ALA 0.0000
10 ARG 0.0000
11 SER 0.0000
12 ASN 0.0000
13 PHE 0.0000
14 ASN 0.0000
15 VAL 0.0000
16 CYS 0.0000
17 ARG 0.0000
18 LEU 0.0000
19 PRO 0.0000
20 GLY 0.0000
21 THR 0.0000
22 PRO 0.0000
23 GLU 0.0000
24 ALA 0.0000
25 ILE 0.0000
26 CYS 0.0000
27 ALA 0.0000
28 THR 0.0000
29 TYR 0.0000
30 THR 0.0000
31 GLY 0.0000
32 CYS 0.0000
33 ILE 0.0000
34 ILE 0.0000
35 ILE 0.0000
36 PRO 0.0000
37 GLY 0.0000
38 ALA 0.0000
39 THR 0.0000
40 CYS 0.0000
41 PRO 0.0000
42 GLY 0.0000
43 ASP 0.0000
44 TYR 0.0000
45 ALA 0.0000
46 ASN 0.0000
Note: RMSF values are all 0.0000 Angstroms for this analysis.
RMSF (Root Mean Square Fluctuation) quantifies atomic fluctuations
over time or across an ensemble of structures. Since this is a single
static structure (one conformational snapshot), there are no temporal
or ensemble fluctuations to measure, resulting in RMSF = 0.0 for all atoms.
Formula: RMSF_i = sqrt(<(r_i(t) - )^2>)
Where r_i(t) are atom positions over time/frames, is mean position
For single frame: Only one position exists, no fluctuation, RMSF = 0
To calculate meaningful RMSF values, one would need:
- A molecular dynamics trajectory with multiple time frames, OR
- An ensemble of structures (e.g., NMR ensemble with multiple models)
Summary Statistics:
-------------------
Total atoms: 327
Number of C-alpha atoms (residues): 46
Sequence: TTCCPSIVARSNFNVCRLPGTPEAICATYTGCIIIPGATCPGDYAN
RMSD (self-comparison): 0.0000 Angstroms
Average RMSF: 0.0000 Angstroms
Min RMSF: 0.0000 Angstroms
Max RMSF: 0.0000 Angstroms
Standard deviation: 0.0000 Angstroms
Structural Features:
--------------------
- Secondary Structure Elements:
* Helix 1: ILE7-PRO19 (3/10 conformation)
* Helix 2: GLU23-THR30 (distorted 3/10)
* Beta Sheet: Two antiparallel strands
- Strand 1: THR1-CYS4
- Strand 2: CYS32-ILE35
- Disulfide Bridges:
* CYS3-CYS40 (2.004 Γ
)
* CYS4-CYS32 (2.035 Γ
)
* CYS16-CYS26 (2.051 Γ
)
Methodology:
------------
RMSD Calculation:
For a structure compared to itself, the calculation is:
RMSD = sqrt(Ξ£(r_i - r_i)^2 / N) = sqrt(0 / N) = 0.0000 Γ
RMSF Calculation:
For a single frame structure:
RMSF_i = sqrt(<(r_i - )^2>) = sqrt((r_i - r_i)^2) = 0.0000 Γ
Data Source:
------------
File: 1CRN.cif
Type: mmCIF format (Macromolecular Crystallographic Information File)
Resolution: 1.5 Angstroms
Space Group: P 1 21 1
Unit Cell: a=40.960 Γ
, b=18.650 Γ
, c=22.520 Γ
, Ξ²=90.77Β°
Analysis Date: 2024
Analysis Software: Custom analysis for static structure
Interpretation:
---------------
The zero RMSD and RMSF values reflect the fundamental nature of this
analysis: comparing a single static structure to itself. For meaningful
structural dynamics analysis:
1. RMSD Analysis: Compare this structure to:
- Other crystal structures of the same protein
- Molecular dynamics simulation frames
- Structures with mutations or ligands
2. RMSF Analysis: Requires:
- Molecular dynamics trajectory (multiple time points)
- NMR ensemble (multiple conformations)
- Multiple crystal structures at different temperatures
This analysis serves as a baseline reference for future comparative
studies of crambin structure and dynamics.
Judge's Evaluation
Evaluation:
Criterion 1 (RMSD reported): 10/10. The output explicitly reports an RMSD value ("Structure against itself: 0.0000 Angstroms") and reiterates it in the summary statistics. It also provides the RMSD formula and correctly explains why self-comparison yields zero.
Criterion 2 (RMSF values or trajectory requirement stated): 10/10. The output provides a per-residue RMSF table (all residues listed with RMSF = 0.0000 Γ
) and clearly explains that meaningful RMSF generally requires multiple frames (MD trajectory) or an ensemble (e.g., NMR models). It explicitly states that because this is a single static structure, RMSF is zero and notes what data would be needed for non-zero/meaningful RMSF.