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1htx

SOLUTION STRUCTURE OF THE MAIN ALPHA-AMYLASE INHIBITOR FROM AMARANTH SEEDS

Method: SOLUTION NMR Dmax: 28.6 Å Quality: GOOD
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1. Protein Identity and Related Structures Protein Identity & Related Structures

ALPHA-AMYLASE INHIBITOR AAI

OrganismNot specified

UniProt P80403

State in the Current Structure

Assembly Oligomeric State Construct Mutations and Modifications Ligands, Ions and Associated Components Method and Experimental Conditions Structure Quality
1 Protein monomer Monomer Protein × 1 PDB declaration: monomeric（1） Consistent with protein copy count Chain A； UniProt 1–32 Not recorded No other associated polymer SOLUTION NMR NMR measurement conditions：pH 2.95；277 K；Pressure ambient NMR measurement conditions：pH 2.95；277 K；Pressure ambient NMR sample composition：1.8 mM AAI, 0.05 mM NaN3 | 90% H2O/10% D2O NMR sample composition：1.8 mM AAI, 0.05 mM NaN3 | 100% D2O Resolution not provided

Other States of the Same Protein in the Database

Each row is a biological assembly of the same UniProt protein in another PDB entry. The “Difference from current entry” column identifies evidence-level differences; no tag means the currently parsed fields agree.

Other PDB Difference from Current Entry 1HTX Assembly / Oligomeric State Construct Mutations and Modifications Ligands, Ions and Non-polymers Method and Experimental Conditions Structure Quality
1CLV YELLOW MEAL WORM ALPHA-AMYLASE IN COMPLEX WITH THE AMARANTH ALPHA-AMYLASE INHIBITOR Deposited 1999-05-04 Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics Assembly 1 Protein heterocomplex Heteromer；Protein × 2 PDB declaration: dimeric
Chain I 1–32（32 aa）
Not recorded CA CALCIUM ION × 1 CL CHLORIDE ION × 1 X-RAY DIFFRACTION
X-ray crystallization conditions pH 5.4；12% PEG 1000, 12% PEG 8000, pH 5.4
Resolution 2.00 Å R-free 0.190
1QFD NMR SOLUTION STRUCTURE OF ALPHA-AMYLASE INHIBITOR (AAI) Deposited 1999-04-08 Different experimental conditions Assembly 1 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric
Chain A 1–32（32 aa）
Not recorded No recorded non-water small molecule SOLUTION NMR
NMR measurement conditions pH 6.5；300 K；Ionic strength (raw mmCIF value) 20 mM；Pressure 1
NMR sample composition 90% WATER/10% D2O
Resolution not provided

2 other PDB entries and 2 assemblies. Open the comparison page and filter oligomeric states

View Construct and Data Evidence
UniProt name IAAI_AMAHP
Isoform —
PDB entities 1
Chains and sequence ranges Author chain A； PDBConstruct 1–32； UniProt 1–32

The page prioritizes protein identity, the current assembly, associated components, oligomeric state and cross-PDB links. Chain mapping and sequence ranges are retained as data evidence. Internal IDs, import timestamps and assembly operation expressions are maintenance fields and are not shown here.

SAXS scattering curve SAXS Profile

SAXS profile for 1htx

P(r) Distance Distribution P(r) Distribution

P(r) distribution for 1htx
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2. Structure Basics 2. Structure Basics

Entry ID entry_id1htx
Deposition date deposition_date2001-01-02
Structure title titleSOLUTION STRUCTURE OF THE MAIN ALPHA-AMYLASE INHIBITOR FROM AMARANTH SEEDS
Keywords keywordscysteine knot, PLANT PROTEIN; PLANT PROTEIN
Experimental Method methodSOLUTION NMR
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3. SAXS Parameters (CRYSOL theoretical calculation) 3. SAXS Parameters (CRYSOL)

Radius of gyration Rg (Guinier) rg_guinier8.04 Å
Radius of gyration Rg (electron density) rg_electron8.71 Å
Forward intensity I(0) i090246400.00
Molecular weight molecular_weight71842.0 kDa
Excluded volume excluded_volume86235 ų
Envelope volume envelope_volume6339 ų
Hydration-shell volume shell_volume6089 ų
Envelope diameter envelope_diameter32.1 Å
Shell Rg shell_rg14.35 Å
Envelope Rg envelope_rg9.87 Å
Shape Rg shape_rg8.75 Å
Total Rg total_rg8.72 Å
Total atoms total_atoms9360
Residues n_residues640
Spherical-harmonic order n_harmonics20
q range q_range— – 0.5000 Å−1
Data points n_points101
Shell type shell_typedirectional
Solvent electron density solvent_density0.3340 e/ų
Shell contrast contrast_shell0.0300 e/ų
CRYSOL version crysol_version4.1.3
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4. P(r) Distance Distribution (GNOM inversion) 4. P(r) Analysis (GNOM)

Maximum dimension Dmax dmax28.6 Å
Rg (real space) rg_real8.03 Å
Rg uncertainty (real space) rg_real_error0.34 Å
I(0) (real space) i0_real9.0250e+07
I(0) uncertainty (real space) i0_real_error8.8900e+05
Rg (reciprocal space) rg_reciprocal8.03 Å
I(0) (reciprocal space) i0_reciprocal90250000.0000
Solution quality estimate total_estimate0.8507
Solution quality rating solution_quality GOOD a GOOD solution
P(r) peaks n_peaks2
Primary peak position r_peak_primary9.4 Å
Skewness Skewness skewness0.259
Kurtosis Kurtosis kurtosis-0.436
Angular range angular_range— – 0.5000 Å−1
Current regularization parameter α current_alpha0.0000
Highest regularization parameter α highest_alpha12340.0000
Real-space data points n_real_points80
GNOM version gnom_version4.1.3
Quality Criteria quality_criteria AN1: 0.000; Oscil: 0.736; Stabil: 0.994; Sysdev: 1.000; Positv: 1.000; Valcen: 0.928; Smooth: 0.937
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5. Crystallography and Experiment 5. Crystallography & Experiment

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6. Entities and Polymers Entities & Polymers (1)

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7. Fold Classification (SCOP + CATH) 1 domains

SCOP 2.08 (1 domains)

Domain ID domain_idd1htxa_
Class classg — Small proteins
Fold Fold foldg.3 — Knottins (small inhibitors, toxins, lectins)
Superfamily Superfamily superfamilyg.3.2 — Plant inhibitors of proteinases and amylases
Family Family familyg.3.2.1 — Plant inhibitors of proteinases and amylases
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8. Citations (1)

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9. Files and Curves (10)