1SAP

HYPERTHERMOPHILE PROTEIN, RELAXATION MATRIX REFINEMENT STRUCTURE


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Submitted: 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Solution structure of the DNA-binding protein Sac7d from the hyperthermophile Sulfolobus acidocaldarius.

Edmondson, S.P.Qiu, L.Shriver, J.W.

(1995) Biochemistry 34: 13289-13304


  • PubMed Abstract: 
  • The Sac7 proteins from the hyperthermophile Sulfolobus acidocaldarius are a heterogeneous mixture of small, thermostable, nonspecific DNA-binding proteins. One of these proteins, Sac7d, has been overexpressed in Escherichia coli to provide a homogene ...

    The Sac7 proteins from the hyperthermophile Sulfolobus acidocaldarius are a heterogeneous mixture of small, thermostable, nonspecific DNA-binding proteins. One of these proteins, Sac7d, has been overexpressed in Escherichia coli to provide a homogeneous preparation for structure, stability, and function studies. We present here essentially complete sequence-specific 1H NMR assignments for Sac7d, a delineation of secondary structural elements, and the high-resolution solution structure obtained from a full relaxation matrix refinement. The final structure provides an excellent fit to the NMR data with an NOE R-factor of 0.27 for backbone NOEs. The structure has a compact globular fold with 82% of the sequence involved in regular secondary structure: an antiparallel two-stranded beta-ribbon with a tight turn, followed by a short 3(10) helix, an antiparallel three-stranded beta-sheet, another short 3(10) helix, and finally four turns of alpha-helix. The amphipathic alpha-helix packs across the hydrophobic face of the three-stranded beta-sheet in an open-faced sandwich arrangement with at least one turn of the helix exposed beyond the sheet. The hydrophobic face of the beta-ribbon packs against a corner of the twisted beta-sheet. The single tryptophan responsible for the 88% fluorescence quenching upon DNA binding is exposed on the surface of the three-stranded beta-sheet. Lysines 5 and 7, whose monomethylation may be associated with enhanced thermostability, are highly solvent exposed along the inner edge of the two-stranded ribbon. The structure of Sac7d differs in many respects from that reported for the homologous native Sso7d [Baumann et al. (1994) Nature Struct. Biol. 1, 808] with a backbone RMSD greater than 3.0 A, largely due to the packing and length of the C-terminal alpha-helix which may be important in Sac7d DNA binding.


    Related Citations: 
    • Noe R-Factors and Structural Refinement Using Firm, an Iterative Relaxation Matrix Program
      Edmondson, S.P.
      (1992) J.Magn.Reson. 98: 283


    Organizational Affiliation

    Department of Medical Biochemistry, School of Medicine, Southern Illinois University, Carbondale 62901, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
SAC7D
A
66Sulfolobus acidocaldarius (strain ATCC 33909 / DSM 639 / JCM 8929 / NBRC 15157 / NCIMB 11770)Mutation(s): 0 
Find proteins for P13123 (Sulfolobus acidocaldarius (strain ATCC 33909 / DSM 639 / JCM 8929 / NBRC 15157 / NCIMB 11770))
Go to UniProtKB:  P13123
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Submitted: 
Software Package:
Software NamePurpose
AMBERrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1995-09-15
    Type: Initial release
  • Version 1.1: 2008-03-24
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2017-11-29
    Type: Derived calculations, Other, Structure summary