Author:
Ladefoged Soren A.,Christiansen Gunna
Abstract
A protein similar to the previously characterized variable surface-exposed membrane protein P120 was identified (P120′), establishing that Mycoplasma hominis PG21 possesses a novel gene family. The gene, p120', was sequenced and found to have some distinctive properties including a putative start codon of GTG, rather than the common ATG codon, and a coding region with a high G+C content, characteristic of essential housekeeping genes in mycoplasmas. No sequence homology was found to known proteins. The genomic locations of the p120 and p120' genes were determined on the restriction map of five M. hominis strains by PFGE. The genes were localized in two separate regions separated by more than 6 kb. Genes as well as proteins corresponding to P120′ were identified in 24/24 M. hominis isolates tested and no size variation was detected. P120′ had a molecular mass of 98 kDa, 20 kDa smaller than P120 as estimated by SDS-PAGE. The protein was surface-exposed and associated with the mycoplasma membrane, but had predominantly hydrophilic characteristics upon Triton X-114 extraction. The N-terminal part of P120′ had a hydrophobic leader sequence without the characteristics of a prolipoprotein. This might explain the membrane association of the protein. Unlike P120, which is frequently recognized by sera of patients seropositive for M. hominis, P120′ was only rarely recognized. The conserved nature of the P120 gene family indicates that it has an essential, although currently unknown, function.
Reference49 articles.
1. Electrophoretic analysis of proteins from Mycoplasma hominis strains detected by SDS-PAGE, two-dimensional gel electrophoresis and immunoblotting.;Andersen;J Gen Microbiol,1987
2. Genome size of mycoplasmal DNA.;Bak;Nature,1969
3. Size and genomic location of the pMGA multigene family of Mycoplasma gallisepticum.;Baseggio;Microbiology,1996
4. Mechanism of antigenic variation in Mycoplasma pulmonis: interwoven, site-specific DNA inversions.;Bhugra;Mol Microbiol,1995
5. Phase separation of integral membrane proteins in Triton X-114 solution.;Bordier;J Biol Chem,1981
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