Organization of Ureaplasma urealyticum urease gene cluster and expression in a suppressor strain of Escherichia coli.
AUTOR(ES)
Neyrolles, O
RESUMO
Ureaplasma urealyticum is a pathogenic ureolytic mollicute which colonizes the urogenital tracts of humans. A genetic polymorphism between the two biotypes of U. urealyticum at the level of the urease genes was found. The urease gene cluster from a biotype 1 representative of U. urealyticum (serotype I) was cloned and sequenced. Seven genes were found, with ureA, ureB, and ureC encoding the structural subunits and ureE, ureF, ureG, and a truncated ureI) gene encoding accessory proteins. Urease expression was not obtained when the plasmid containing these genes was incorporated into an opal suppressor strain of Escherichia coli, although this enzymatic activity was found in the same E. coli strain transformed with pC6b, a plasmid with previously cloned urease genes from the U. urealyticum T960 strain of biotype 2 (serotype 8). Although there are 12 TGA triplets encoding tryptophan within urease genes, the level of expression obtained was comparable to the levels reported for other bacterial genes expressed in E. coli. Nested deletion experiments allowed us to demonstrate that ureD is necessary for urease activity whereas another open reading frame located downstream is not. The promoter for ureA and possibly other urease genes was identified for both serotypes.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=177707Documentos Relacionados
- Organization of Ureaplasma urealyticum urease gene cluster and expression in a suppressor strain of Escherichia coli.
- Cloning, sequencing, and expression of thermophilic Bacillus sp. strain TB-90 urease gene complex in Escherichia coli.
- Characteristics of Ureaplasma urealyticum urease.
- Isolation and detection of urease genes in Ureaplasma urealyticum.
- Cloning and characterization of tetM gene from a Ureaplasma urealyticum strain.