1GOC

COOPERATIVE STABILIZATION OF ESCHERICHIA COLI RIBONUCLEASE HI BY INSERTION OF GLY-80B AND GLY-77-> ALA SUBSTITUTION


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Cooperative stabilization of Escherichia coli ribonuclease HI by insertion of Gly-80b and Gly-77-->Ala substitution.

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

(1993) Biochemistry 32: 7136-7142

  • Primary Citation of Related Structures:  1GOA, 1GOB

  • PubMed Abstract: 
  • The insertion of a Gly residue (designated as Gly-80b) between the C-cap of the alpha II-helix (Gln-80) and the N-cap of the alpha III-helix (Trp-81) in Escherichia coli ribonuclease HI enhances the protein stability by 0.4 kcal/mol in delta G (Kimur ...

    The insertion of a Gly residue (designated as Gly-80b) between the C-cap of the alpha II-helix (Gln-80) and the N-cap of the alpha III-helix (Trp-81) in Escherichia coli ribonuclease HI enhances the protein stability by 0.4 kcal/mol in delta G (Kimura, S., Nakamura, H., Hashimoto, T., Oobatake, M., & Kanaya, S. (1992) J. Biol. Chem. 267, 21535-21542). Another mutation within the alpha II-helix, Gly-77-->Ala, reduces the stability by 0.9 kcal/mol. Simultaneous introduction of these mutations enhances the stability by 0.8 kcal/mol, indicating that the effects of these mutations are cooperative and not simply independent. We determined the crystal structures of these three mutant proteins (G80b-, A77-, and A77/G80b-RNase H) to investigate this cooperative mechanism of the protein stabilization. The structures revealed that the inserted Gly-80b assumes a left-handed helical conformation in both the G80b- and the A77/G80b-RNase H. This inserted glycine residue allows the formation of a "paperclip", which is a common motif at the C-termini of alpha-helices. Accompanying the formation of the paperclip motif, two intrahelical hydrogen bonds are formed between the backbone atoms (O78-N80b and O80b-N84). The stabilization caused by the insertion of Gly-80b can be ascribed to the formation of these hydrogen bonds. The Gly-77-->Ala substitution destabilizes the protein due to the deformed packing interactions in the hydrophobic core around Ala-77 and the stress in the wedged indole ring of Trp-81. These effects are alleviated by the insertion of Gly-80b, which relaxes the backbone structure.(ABSTRACT TRUNCATED AT 250 WORDS)


    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 to 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
    • 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


    Organizational Affiliation

    Protein Engineering Research Institute, Osaka, Japan.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
RIBONUCLEASE H
A
156Escherichia coli (strain K12)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: 2 Å
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 44.980α = 90.00
b = 86.450β = 90.00
c = 35.380γ = 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