Biological Assembly 1  

 3D View: Structure

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 1 generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 45.35 kDa 
• Atom Count: 2897 
• Residue Count: 365 
• Unique protein chains: 1

1QMN

Alpha1-antichymotrypsin serpin in the delta conformation (partial loop insertion)

• DOI: 10.2210/pdb1QMN/pdb

• Classification: HYDROLASE INHIBITOR
• Organism(s): Homo sapiens
• Expression System: Escherichia coli
• Mutation(s): Yes 


• Deposited: 1999-10-04 Released: 2000-01-17 
• Deposition Author(s): Gooptu, B., Hazes, B., Lomas, D.A.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.27 Å
• R-Value Free: 0.243 
• R-Value Work: 0.197 
• R-Value Observed: 0.197 

Literature

Inactive Conformation of the Serpin Alpha1-Antichymotrypsin Indicates Two-Stage Insertion of the Reactive Loop: Implications for Inhibitory Function and Conformational Disease

Gooptu, B., Hazes, B., Chang, W.-S.W., Dafforn, T.R., Carrell, R.W., Read, R.J., Lomas, D.A.

(2000) Proc Natl Acad Sci U S A 97: 67

• PubMed: 10618372 
• DOI: 10.1073/pnas.97.1.67
• Structures With Same Primary Citation


• PubMed Abstract: 
  

The serpins are a family of proteinase inhibitors that play a central role in the control of proteolytic cascades. Their inhibitory mechanism depends on the intramolecular insertion of the reactive loop into beta-sheet A after cleavage by the target proteinase. Point mutations within the protein can allow aberrant conformational transitions characterized by beta-strand exchange between the reactive loop of one molecule and beta-sheet A of another. These loop-sheet polymers result in diseases as varied as cirrhosis, emphysema, angio-oedema, and thrombosis, and we recently have shown that they underlie an early-onset dementia. We report here the biochemical characteristics and crystal structure of a naturally occurring variant (Leu-55-Pro) of the plasma serpin alpha(1)-antichymotrypsin trapped as an inactive intermediate. The structure demonstrates a serpin configuration with partial insertion of the reactive loop into beta-sheet A. The lower part of the sheet is filled by the last turn of F-helix and the loop that links it to s3A. This conformation matches that of proposed intermediates on the pathway to complex and polymer formation in the serpins. In particular, this intermediate, along with the latent and polymerized conformations, explains the loss of activity of plasma alpha(1)-antichymotrypsin associated with chronic obstructive pulmonary disease in patients with the Leu-55-Pro mutation.

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Organizational Affiliation: 

Respiratory Medicine Unit, Department of Medicine University of Cambridge, United Kingdom.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details
ALPHA-1-ANTICHYMOTRYPSIN	A	401	Homo sapiens	Mutation(s): 1  Gene Names: SERPINA3, AACT, GIG24, GIG25
Find proteins for P01011 (Homo sapiens) Go to UniProtKB:  P01011
NIH Common Fund Data Resources
PHAROS  P01011 GTEx  ENSG00000196136

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.27 Å
• R-Value Free: 0.243 
• R-Value Work: 0.197 
• R-Value Observed: 0.197 
• Space Group: P 1 2₁ 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 41.723	α = 90
b = 122.094	β = 101.03
c = 41.724	γ = 90

Software Package:

Software Name	Purpose
CNS	refinement
MOSFLM	data reduction
SCALA	data scaling
AMoRE	phasing

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 1999-10-04 
• Released Date: 2000-01-17 
Deposition Author(s): Gooptu, B., Hazes, B., Lomas, D.A.

Revision History 

• Version 1.0: 2000-01-17
  Type: Initial release
  
• Version 1.1: 2012-11-28
  Changes: Database references, Derived calculations, Other, Refinement description, Structure summary, Version format compliance
• Version 1.2: 2019-05-08
  Changes: Data collection, Experimental preparation, Other