1LTM

ACCELERATED X-RAY STRUCTURE ELUCIDATION OF A 36 KDA MURAMIDASE/TRANSGLYCOSYLASE USING WARP


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.7 Å
  • R-Value Free: 0.221 
  • R-Value Work: 0.186 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Accelerated X-ray structure elucidation of a 36 kDa muramidase/transglycosylase using wARP.

Van Asselt, E.J.Perrakis, A.Kalk, K.H.Lamzin, V.S.Dijkstra, B.W.

(1998) Acta Crystallogr.,Sect.D 54: 58-73


  • PubMed Abstract: 
  • The X-ray structure of the 36 kDa soluble lytic transglycosylase from Escherichia coli has been determined starting with the multiple isomorphous replacement method with inclusion of anomalous scattering at 2.7 A resolution. Subsequently, before any ...

    The X-ray structure of the 36 kDa soluble lytic transglycosylase from Escherichia coli has been determined starting with the multiple isomorphous replacement method with inclusion of anomalous scattering at 2.7 A resolution. Subsequently, before any model building was carried out, phases were extended to 1.7 A resolution with the weighted automated refinement procedure wARP, which gave a dramatic improvement in the phases. The electron-density maps from wARP were of outstanding quality for both the main chain and the side chains of the protein, which allowed the time spent on the tracing, interpretation and building of the X-ray structure to be substantially shortened. The structure of the soluble lytic transglycosylase was refined at 1.7 A resolution with X-PLOR to a final crystallographic R factor of 18.9%. Analysis of the wARP procedure revealed that the use of the maximum-likelihood refinement in wARP gave much better phases than least-squares refinement, provided that the ratio of reflections to protein atom parameters was approximately 1.8 or higher. Furthermore, setting aside 5% of the data for an Rfree test set had a negative effect on the phase improvement. The mean WwARP, a weight determined at the end of the wARP procedure and based on the variance of structure factors from six individually refined wARP models, proved to be a better indicator than the Rfree factor to judge different phase improvement protocols. The elongated Slt35 structure has three domains named the alpha, beta and core domains. The alpha domain contains mainly alpha-helices, while the beta domain consists of a five-stranded antiparallel beta-sheet flanked by a short alpha-helix. Sandwiched between the alpha and beta domains is the core domain, which bears some resemblance to the fold of the catalytic domain of the previously elucidated 70 kDa soluble lytic transglycosylase from E. coli. The putative active site is at the bottom of a large deep groove in the core domain.


    Organizational Affiliation

    BIOSON Research Institute and Laboratory of Biophysical Chemistry, Groningen University, Nijenborgh 4, 9747 AG Groningen, The Netherlands.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
36 KDA SOLUBLE LYTIC TRANSGLYCOSYLASE
A
320Escherichia coli (strain K12)Gene Names: mltB
EC: 4.2.2.n1
Find proteins for P41052 (Escherichia coli (strain K12))
Go to UniProtKB:  P41052
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NA
Query on NA

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A
SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
 Ligand Interaction
BCN
Query on BCN

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Download CCD File 
A
BICINE
C6 H13 N O4
FSVCELGFZIQNCK-UHFFFAOYSA-N
 Ligand Interaction
EDO
Query on EDO

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Download CCD File 
A
1,2-ETHANEDIOL
ETHYLENE GLYCOL
C2 H6 O2
LYCAIKOWRPUZTN-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.7 Å
  • R-Value Free: 0.221 
  • R-Value Work: 0.186 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 58.329α = 90.00
b = 67.883β = 90.00
c = 98.853γ = 90.00
Software Package:
Software NamePurpose
ARP/wARPmodel building
PHASESphasing
X-PLORmodel building
DENZOdata reduction
SCALEPACKdata scaling
X-PLORphasing
X-PLORrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1998-11-11
    Type: Initial release
  • Version 1.1: 2008-03-24
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance