J. Maddock et al., IDENTIFICATION OF AN ESSENTIAL CAULOBACTER-CRESCENTUS GENE ENCODING AMEMBER OF THE OBG FAMILY OF GTP-BINDING PROTEINS, Journal of bacteriology, 179(20), 1997, pp. 6426-6431
We have identified an essential Caulobacter crescentus gene (cgtA) tha
t encodes a member of a recently identified subfamily of GTPases (the
Obg family) conserved from Bacteria to Archaea to humans, This evoluti
onary conservation between distantly related species suggests that thi
s family of GTP-binding proteins possesses a fundamental, yet unknown,
cellular role, In this report, we describe the isolation and sequence
of the cgtA gene, The predicted CgtA protein displays striking simila
rity to the Obg family of small, monomeric GTP-binding proteins, both
in the conserved guanine nucleotide-binding domains and throughout the
N-terminal glycine-rich domain that is found in many members of the O
bg family. Disruption of the cgtA gene was lethal, demonstrating that
this gene is essential for cell growth, Immunoblot analysis revealed t
hat CgtA protein levels remained constant throughout the C. crescentus
cell cycle.