Essential genes of a minimal bacterium

doi:10.1073/pnas.0510013103

Essential genes of a minimal bacterium

Synthetic Biology Group, J. Craig Venter Institute, 9704 Medical Center Drive, Rockville, MD 20850

Contributed by Hamilton O. Smith, November 18, 2005

Abstract

Mycoplasma genitalium has the smallest genome of any organism that can be grown in pure culture. It has a minimal metabolism and little genomic redundancy. Consequently, its genome is expected to be a close approximation to the minimal set of genes needed to sustain bacterial life. Using global transposon mutagenesis, we isolated and characterized gene disruption mutants for 100 different nonessential protein-coding genes. None of the 43 RNA-coding genes were disrupted. Herein, we identify 382 of the 482 M. genitalium protein-coding genes as essential, plus five sets of disrupted genes that encode proteins with potentially redundant essential functions, such as phosphate transport. Genes encoding proteins of unknown function constitute 28% of the essential protein-coding genes set. Disruption of some genes accelerated M. genitalium growth.

Footnotes

↵ * To whom correspondence should be addressed. E-mail: hsmith{at}venterinstitute.org.
Author contributions: J.I.G., N.A.-G., C.A.H., H.O.S., and J.C.V. designed research; J.I.G., N.A.-G., N.A., M.R.L., and M.M. performed research; J.I.G. contributed new reagents/analytic tools; J.I.G. and S.Y. analyzed data; and J.I.G., C.A.H., and H.O.S. wrote the paper.
Conflict of interest statement: No conflicts declared.
Data deposition: The sequence reported in this paper has been deposited in the GenBank database (Mycoplasma genitalium G37 ATCC 33530 genomic sequence; accession no. L43967).
Freely available online through the PNAS open access option.