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ATP hydrolysis in rho: identifying the residues and their roles
Author(s) -
Balasubramanian Krithika,
Stitt Barbara
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.608.1
Subject(s) - atp hydrolysis , helicase , biochemistry , hydrolysis , chemistry , nucleotide , atpase , escherichia coli , dna , mutant , site directed mutagenesis , binding site , active site , stereochemistry , rna , enzyme , gene
Escherichia coli transcription termination factor rho is an RNA/DNA helicase that terminates transcription using energy derived from the hydrolysis of ATP. The ATP binding sites of rho are located at the interfaces of adjoining C‐terminal domains and have the Walker A and B motifs, characteristic of many ATPases (Skordalakes & Berger, 2003; Richardson 2002). Available rho crystal structures capture the protein with its active site in an open configuration that must close to permit ATP hydrolysis. Because of this, the identity of active site residues predicted to mediate ATP hydrolysis is uncertain. To determine which amino acids activate water, stabilize transition state, sense the γ‐phosphoryl group, and coordinate the magnesium ion of MgATP, we are carrying out site‐specific mutagenesis on candidate residues which are conserved across bacterial species, and characterizing the relevant properties of the mutant proteins. Support: Commonwealth Universal Research Enhancement Program, Pennsylvania Department of Health