1RBT

STRUCTURAL STUDY OF MUTANTS OF ESCHERICHIA COLI RIBONUCLEASE HI WITH ENHANCED THERMOSTABILITY


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Structural study of mutants of Escherichia coli ribonuclease HI with enhanced thermostability.

Ishikawa, K.Kimura, S.Kanaya, S.Morikawa, K.Nakamura, H.

(1993) Protein Eng. 6: 85-91

  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Systematic replacement of the amino acid residues in Escherichia coli ribonuclease HI with those in the thermophilic counterpart has revealed that two mutations, His62-->Pro (H62P) and Lys95-->Gly (K95G), increased the thermostability of the protein. ...

    Systematic replacement of the amino acid residues in Escherichia coli ribonuclease HI with those in the thermophilic counterpart has revealed that two mutations, His62-->Pro (H62P) and Lys95-->Gly (K95G), increased the thermostability of the protein. These single-site mutant proteins, together with the mutant proteins His62-->Ala (H62A), Lys95-->Asn (K95N) and Lys95-->Ala (K95A), were crystallized and their structures were determined at 1.8 A resolution. The crystal structures of these mutant proteins reveal that only the local structure around each mutation site is essential for the increase in thermostability. For each mutant protein, the stabilization mechanism is considered to be as follows: (i) H62P is stabilized because of a decrease in the entropy of the unfolded state, without a change in the native backbone structure; (ii) K95G is stabilized since the strain caused by the left-handed backbone structure in the typical 3:5 type loop is eliminated; and (iii) K95N is slightly stabilized by a hydrogen bond formed between the side-chain N delta-atom of the mutated aspargine residue and the main-chain carbonyl oxygen within the same residue.


    Related Citations: 
    • Three-Dimensional Structure of Ribonuclease H from E. Coli
      Katayanagi, K.,Miyagawa, M.,Matsushima, M.,Ishikawa, M.,Kanaya, S.,Ikehara, M.,Matsuzaki, T.,Morikawa, K.
      (1990) Nature 347: 306
    • Structural Details of Ribonuclease H from Escherichia Coli as Refined at an Atomic Resolution
      Katayanagi, K.,Miyagawa, M.,Matsushima, M.,Ishikawa, M.,Kanaya, S.,Nakamura, H.,Ikehara, M.,Matsuzaki, T.,Morikawa, K.
      (1992) J.Mol.Biol. 223: 1029


    Organizational Affiliation

    Protein Engineering Research Institute, Osaka, Japan.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
RIBONUCLEASE H
A
155Escherichia coli (strain K12)Mutation(s): 0 
Gene Names: rnhA (dasF, herA, rnh, sdrA)
EC: 3.1.26.4
Find proteins for P0A7Y4 (Escherichia coli (strain K12))
Go to UniProtKB:  P0A7Y4
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 44.040α = 90.00
b = 86.630β = 90.00
c = 35.480γ = 90.00
Software Package:
Software NamePurpose
PROLSQrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1994-01-31
    Type: Initial release
  • Version 1.1: 2008-03-03
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2017-11-29
    Type: Derived calculations, Other