Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
, 103 (2), 425-30

Essential Genes of a Minimal Bacterium

Affiliations

Essential Genes of a Minimal Bacterium

John I Glass et al. Proc Natl Acad Sci U S A.

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.

Figures

Fig. 1.
Fig. 1.
Accumulation of new disrupted M. genitalium genes (red) and new transposon insertion sites in the genome (black) as a function of the total number of analyzed primary colonies and subcolonies with insertion sites different from that of the parental primary clone.
Fig. 2.
Fig. 2.
Global transposon mutagenesis of M. genitalium. The locations of transposon insertions from the current study are noted by a Δ below the insertion site on the map. Insertions mapped in our previous study (4) are noted with a ▿. Sites with 10 or more insertions are noted by a red filled triangle (▴).
Fig. 3.
Fig. 3.
Metabolic pathways and substrate transport mechanisms encoded by M. genitalium. Metabolic products are colored red, and mycoplasma proteins are black. White letters on black boxes mark nonessential functions or proteins based on our current gene disruption study. Question marks denote enzymes or transporters not identified that would be necessary to complete pathways, and those missing enzyme and transporter names are colored green. Transporters are colored according to their substrates: yellow, cations; green, anions and amino acids; orange, carbohydrates; purple, multidrug and metabolic end product efflux. The arrows indicate the predicted direction of substrate transport. The ABC type transporters are drawn as follows: rectangle, substrate-binding protein; diamonds, membrane-spanning permeases; circles, ATP-binding subunits.

Similar articles

  • The Minimal Cellular Genome of Mycoplasma
    S Razin. Indian J Biochem Biophys 34 (1-2), 124-30. PMID 9343940.
    The mycoplasmas are the smallest and simplest self-replicating organisms, being built of a plasma membrane, ribosomes, and a circular double-stranded DNA molecule-the typ …
  • Mycoplasma Genitalium mg200 and mg386 Genes Are Involved in Gliding Motility but Not in Cytadherence
    OQ Pich et al. Mol Microbiol 60 (6), 1509-19. PMID 16796684.
    Isolation and characterization of transposon-generated Mycoplasma genitalium gliding-deficient mutants has implicated mg200 and mg386 genes in gliding motility. The propo …
  • A Genome-Scale Metabolic Reconstruction of Mycoplasma Genitalium, iPS189
    PF Suthers et al. PLoS Comput Biol 5 (2), e1000285. PMID 19214212.
    With a genome size of approximately 580 kb and approximately 480 protein coding regions, Mycoplasma genitalium is one of the smallest known self-replicating organisms and …
  • Comparative Genomics of Mycoplasmas
    S Razin. Wien Klin Wochenschr 109 (14-15), 551-6. PMID 9286058. - Review
    The mycoplasmas are the smallest and simplest self-replicating organisms. The goal of defining in molecular terms the entire machinery of a living cell by using mycoplasm …
  • Building the Blueprint of Life
    C Henry et al. Biotechnol J 5 (7), 695-704. PMID 20665643. - Review
    With recent breakthroughs in experimental microbiology making it possible to synthesize and implant an entire genome to create a living cell, the challenge of constructin …
See all similar articles

Cited by 308 PubMed Central articles

See all "Cited by" articles

Publication types

MeSH terms

Associated data

LinkOut - more resources

Feedback