3MYW

The Bowman-Birk type inhibitor from mung bean in ternary complex with porcine trypsin


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

The 0.25-nm X-ray structure of the Bowman-Birk-type inhibitor from mung bean in ternary complex with porcine trypsin.

Lin, G.Bode, W.Huber, R.Chi, C.Engh, R.A.

(1993) Eur.J.Biochem. 212: 549-555


  • PubMed Abstract: 
  • The structure of the Bowman-Birk-type inhibitor from mung bean Phaseolus aureus has been determined in ternary complex with porcine trypsin. The complex formed crystals of the trigonal space group P3(1)21 which diffracted to a resolution of 250 pm. E ...

    The structure of the Bowman-Birk-type inhibitor from mung bean Phaseolus aureus has been determined in ternary complex with porcine trypsin. The complex formed crystals of the trigonal space group P3(1)21 which diffracted to a resolution of 250 pm. Each of the two mung bean protease reactive sites is bound to trypsin according to the standard mechanism for serine proteinase inhibition. The binding loops thereby adopt the canonical conformation for the standard mechanism; however, the sub-van der Waals contact between the active-site serine O gamma (195) and the P1 carbonyl carbon of both loops is significantly smaller (210 pm) than hitherto observed, with continuous electron density connecting the two atoms. The inhibitor is formed by two double-stranded antiparallel beta-sheets, which are connected into a moderately twisted beta-sheet by a network of hydrogen bonds involving main-chain atoms and two water molecules. All contacts with neighbors in the crystal lattice occur between trypsin molecules. This apparently gives rise to an unusual form of disorder where the complexes pack in two orientations Ta:MaMb:Tb and Tb:MbMa:Ta (Ta, Tb = trypsin, Ma = mung bean loop I, Mb = mung bean loop II), such that the asymmetric unit consists of the ternary complex in two orientations, each with half occupancy. This is nearly equivalent to an asymmetric unit which has one trypsin molecule with full occupancy and one mung bean inhibitor with half occupancy and a crystallographic twofold symmetry axis through its center. Because of the approximate twofold symmetry of the inhibitor itself, however, the electron density was interpretable for most of the inhibitor (17 residues at the termini were not resolved) and shows evidence of its double orientation.


    Organizational Affiliation

    Shanghai Institute of Biochemistry, People's Republic of China.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Trypsin
A, B
223Sus scrofaMutation(s): 0 
EC: 3.4.21.4
Find proteins for P00761 (Sus scrofa)
Go to UniProtKB:  P00761
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Bowman-Birk type trypsin inhibitor
I
72Vigna radiata var. radiataMutation(s): 0 
Find proteins for P01062 (Vigna radiata var. radiata)
Go to UniProtKB:  P01062
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CA
Query on CA

Download SDF File 
Download CCD File 
A, B
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • Space Group: P 31
Unit Cell:
Length (Å)Angle (°)
a = 62.460α = 90.00
b = 62.460β = 90.00
c = 160.010γ = 120.00
Software Package:
Software NamePurpose
X-PLORrefinement
PROTEINphasing
PROTEINmodel building
MADNESSdata collection
PROTEINdata reduction
PROTEINdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2010-12-29
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance
  • Version 1.2: 2017-11-08
    Type: Advisory, Refinement description
  • Version 1.3: 2018-04-18
    Type: Data collection