Overexpression of the cgtA (yhbZ, obgE) gene, coding for an essential GTP-binding protein, impairs the regulation of chromosomal functions in Escherichia coli.
GTPases belonging to the Obg/Gtp1 subfamily are essential proteins in most bacterial species and are evolutionarily conservative from bacteria to humans. However, their specific functions in the regulation of cellular processes are largely unknown. Here we demonstrate that overproduction of a member of the Obg/Gtp1 subfamily, cgtA ( yhbZ, obgE) gene product, in Escherichia coli is deleterious for bacterial growth. However, syntheses of DNA, RNA, and proteins were not significantly affected under these conditions as measured by efficiency of incorporation of radioactive precursors. On the other hand, flow cytometry studies revealed that cgtA-overexpressing bacteria form enlarged cells with significantly changed distribution of chromosomal DNA. These results strongly suggest that overproduction of a GTP-binding protein from the Obg/Gtp1 subfamily impairs regulation of some chromosomal functions in E. coli, especially synchronization of DNA replication initiation and possibly also partitioning of daughter chromosomes after a replication round.
Dutkiewicz
Rafal
R
Department of Molecular and Cellular Biology, Institute of Biotechnology, Intercollegiate Faculty of Biotechnology of the University of Gdańsk and Medical University of Gdańsk, Kladki 24, Poland.
Slomińska
Monika
M
Wegrzyn
Grzegorz
G
Czyz
Agata
A
D001426:Bacterial Proteins; D002876:Chromosomes, Bacterial / Q000235:genetics*; D004261:DNA Replication; D004926:Escherichia coli / Q000235:genetics / Q000254:growth & development*; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial; D020043:Genes, Essential; D020559:Monomeric GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; C108621:CgtA protein, bacteria; C491572:ObgE protein, E coli; D020559:Monomeric GTP-Binding Proteins