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Mechanochemical ATPases and transcriptional activation
Author(s) -
Zhang X.,
Chaney M.,
Wigneshweraraj Siva R.,
Schumacher J.,
Bordes P.,
Can W.,
Buck M.
Publication year - 2002
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1046/j.1365-2958.2002.03065.x
Subject(s) - biology , atp hydrolysis , rna polymerase , chaperone (clinical) , microbiology and biotechnology , biochemistry , gtpase , atpase , polymerase , activator (genetics) , rna , dna , biophysics , enzyme , gene , medicine , pathology
Summary Transcriptional activator proteins that act upon the σ 54 ‐containing form of the bacterial RNA polymerase belong to the extensive AAA + superfamily of ATPases, members of which are found in all three kingdoms of life and function in diverse cellular processes, often via chaperone‐like activities. Formation and collapse of the transition state of ATP for hydrolysis appears to engender the interaction of the activator proteins with σ 54 and leads to the protein structural transitions needed for RNA polymerase to isomerize and engage with the DNA template strand. The common oligomeric structures of AAA + proteins and the crea‐tion of the active site for ATP hydrolysis between protomers suggest that the critical changes in protomer structure required for productive interactions with σ 54 ‐holoenzyme occur as a consequence of sensing the state of the γ ‐phosphate of ATP. Depending upon the form of nucleotide bound, different functional states of the activator are created that have distinct substrate and chaperone‐like binding activ‐ities. In particular, interprotomer ATP interactions rely upon the use of an arginine finger, a situation reminiscent of GTPase‐activating proteins.