Author Archives: Sarah Hunter

C-H-Ras P21 Protein

PDB ID:   5P21

Number of Polypeptide Chains in the Protein:   1

Chain Designation:  

Chain 1: A

Gene Names:  

HRAS1

PDB Deposition Title:  

Refined crystal structure of the triphosphate conformation of H-ras p21 at 1.35 A resolution: implications for the mechanism of GTP hydrolysis.

Primary Citation Title:  

Refined crystal structure of the triphosphate conformation of H-ras p21 at 1.35 A resolution: implications for the mechanism of GTP hydrolysis.

Citation Authors:  

Pai, E.F., Krengel, U., Petsko, G.A., Goody, R.S., Kabsch, W., Wittinghofer, A.

Citation Journal:  

(1990) EMBO J. 9: 2351-2359

Related PDB Entries:  

1AA9, 1AGP, 1BKD, 1CLU, 1CRP

 


Information for Chain A;  UniprotKB Accession Number:  P01112

Primary Structure

Length of the Chain (from Uniprot P01112):  189

FASTA Sequence for the chain (from Uniprot P01112):

>sp|P01112|RASH_HUMAN GTPase HRas OS=Homo sapiens GN=HRAS PE=1 SV=1
MTEYKLVVVGAGGVGKSALTIQLIQNHFVDEYDPTIEDSYRKQVVIDGETCLLDILDTAG
QEEYSAMRDQYMRTGEGFLCVFAINNTKSFEDIHQYREQIKRVKDSDDVPMVLVGNKCDL
AARTVESRQAQDLARSYGIPYIETSAKTRQGVEDAFYTLVREIRQHKLRKLNPPDESGPG
CMSCKCVLS

Secondary Structures (DSSP defined; from RCSB PDB)

Helical Structures:  Number of Helices:  7;  Percentage of Residues:  36

Beta Strands:  Number of Strands:  6;  Percentage of Residues:  26

Secondary Structure Map:

 

Tertiary Structure

Number of Domains Along Chain A:  1

CATH Domain IDs:  5p21A00

CATH Classes:  A00: Alpha Beta

CATH Architectures:  A00: 3-Layer(aba) Sandwich

CATH Topologies:  A00: Rossmann fold

Topological Diagrams:

 

 

Function and Ligand Binding Site

Excerpt from Abstract:

In one of these conformations, the side chain of Gln61 makes contact with a water molecule, which is perfectly placed to be the nucleophile attacking the gamma-phosphate of GTP. Based on this observation, we propose a mechanism for GTP hydrolysis involving mainly Gln61 and Glu63 as activating species for in-line attack of water. Nucleophilic displacement is facilitated by hydrogen bonds from residues Thr35, Gly60 and Lys16. A mechanism for rate enhancement by GAP is also proposed.

Description of Function from Uniprot:

Ras proteins bind GDP/GTP and possess intrinsic GTPase activity.

Selected Molecular Function GO Terms:

GO ID: 0005525, Name: GTP Binding, Definition: Interacting selectively and non-covalently with GTP, guanosine triphosphate.

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GO ID: 0008022, Name: Protein C-terminus Binding, Definition: Interacting selectively and non-covalently with a protein C-terminus, the end of any peptide chain at which the 1-carboxy function of a constituent amino acid is not attached in peptide linkage to another amino-acid residue.

EC Number:   N/A

EC Description:   

N/A

Major Organic Ligand:   PHOSPHOAMINOPHOSPHONIC ACID-GUANYLATE ESTER

Ligand Binding Residues:

Gly 12, Gly 13, Val 14, Gly 15, Lys 16, Ser 17, Ala 18, Phe 28, Val 29, Asp 30, Pro 34, Thr 35, Gly 60, Asn 116, Lys 117, Asp 119, Leu 120, Ser 145, Ala 146, Lys 147

Ligand Binding Site: