Mycoplasma GenitaliumMycoplasma Genitalium

Genome ProjectGenome Project

Sharndeep Kaur

GenomeGenome

Name:Name: Mycoplasma genitalium G- Mycoplasma genitalium G-3737

Kingdom:Kingdom: Bacteria Bacteria IntermediateIntermediate

1. Firmicutes1. Firmicutes2. Bacillus/Clostridium group2. Bacillus/Clostridium group3. Mollicutes3. Mollicutes

4.Mycoplasmataceae4.Mycoplasmataceae Genus:Genus: Mycoplasma Mycoplasma Species:Species: genitalium Strain G-37 genitalium Strain G-37

BackgroundBackgroundMycoplasmasMycoplasmas

Mycoplasmas are members of the class Mollicutes and comprise a large group of bacteria which lack a cell wall, have small genomes, and a characteristically low

G+ C content.

These diverse organisms are parasites for a wide range of hosts including humans, animals, insects, plants, and cells grown in tissue culture.

Mycoplasmas are of interest because they are believed to represent a minimal life form, having yielded to selective pressure to reduce genome size.

BackgroundBackgroundMycoplasma GenitaliumMycoplasma Genitalium

Mycoplasma genitalium has the smallest genome size of 580 kb

Lacks cell wall

A gram-positive bacterium, is believed to be the cause of non-gonococcal urethritis (NGU)

Causes reproductive-tract infections

Urogenital tract may be the primary site of infection

Exists in parasitic association with ciliated epithelial cells of primate genital and respiratory tracts

Common name: Tully JG et al. or G-37

Mycoplasmas were initially mistaken Mycoplasmas were initially mistaken for viruses because they can pass for viruses because they can pass through 0.45 µm filters. This is through 0.45 µm filters. This is attributable not only to their small attributable not only to their small size, but also the flexibility of their size, but also the flexibility of their cell envelope.cell envelope.

Only a few strains have been Only a few strains have been cultivatedcultivated

Background Background continuescontinues

Background Background continuescontinues

Analysis of rRNAs and tRNAs from mycoplasmas suggests that M. Genitalium arose through loss of genetic material from low G+C gram-positive ancestors of the Lactobacillus-Clostridium branch of the phylogenetic tree

Molecular characterization of the M. genitalium genome is hindered by the difficulty in applying classical genetics to the study of this and other mycoplasmas, and the lack of available auxotrophic mutants due to the requirement of this organism for complex media for growth in culture

Why do biologists want to Why do biologists want to study this organism?study this organism?

Because it is considered to be the Because it is considered to be the organism (not counting viruses) with organism (not counting viruses) with the smallest genomethe smallest genome

Sequenced by Fraser et al.

Completed: Jan 8, 2001Completed: Jan 8, 2001

Sequencing Center: TIGR Funding Center: DOE Publication: PUBMED abstract

Sequence information

Genome Stats:Genome Stats: The complete nucleotide sequence is 580,070

base pairs (smallest known genome of any free-living organism)

A total of only 470 predicted coding regions were identified that include genes required for DNA replication, transcription and translation, DNA repair, cellular transport, and energy metabolism.

Low G+C % content (32%)

UGA, normally a stop codon, encodes for the amino acid tryptophan.

Genome LinksGenome Links

www.Genome.ucsc.eduwww.Genome.ucsc.edu

http://gnn.tigr.org/main.shtmlhttp://gnn.tigr.org/main.shtml

http://www.ncbi.nlm.nih.govhttp://www.ncbi.nlm.nih.gov

http://www.tigr.org/tigr-scripts/CMR2/Genohttp://www.tigr.org/tigr-scripts/CMR2/GenomePage3.spl?database=gmgmePage3.spl?database=gmg

http://www.ncbi.nlm.nih.gov/entrez/query.fhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=nucleotide&list_uidcgi?cmd=Retrieve&db=nucleotide&list_uids=12044850&dopt=GenBanks=12044850&dopt=GenBank