The solution structure of ChaB, a putative membrane ion antiporter regulator from Escherichia coli.
BACKGROUND
ChaB is a putative regulator of ChaA, a Na+/H+ antiporter that also has Ca+/H+ activity in E. coli. ChaB contains a conserved 60-residue region of unknown function found in other bacteria, archaeabacteria and a series of baculoviral proteins. As part of a structural genomics project, the structure of ChaB was elucidated by NMR spectroscopy.


RESULTS
The structure of ChaB is composed of 3 alpha-helices and a small sheet that pack tightly to form a fold that is found in the cyclin-box family of proteins.


CONCLUSIONS
ChaB is distinguished from its putative DNA binding sequence homologues by a highly charged flexible loop region that has weak affinity to Mg2+ and Ca2+ divalent metal ions.
Department of Biochemistry, McGill University, 3655 Promenade Sir William Osler, Montreal, Quebec, Canada, H3G 1Y6. mike@bri.nrc.ca
Michael J
MJ
Osborne
Nadeem
N
Siddiqui
Pietro
P
Iannuzzi
Kalle
K
Gehring
D002412:Cations / Q000378:metabolism; D003001:Cloning, Molecular / Q000379:methods; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics / Q000502:physiology; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods; D010455:Peptides / Q000502:physiology; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary / Q000502:physiology; D019831:Sodium-Calcium Exchanger / Q000502:physiology
D002412:Cations; C500388:ChaB protein, E coli; D029968:Escherichia coli Proteins; D010455:Peptides; D019831:Sodium-Calcium Exchanger