The divergently transcribed Streptococcus parasanguis virulence-associated fimA operon encoding an Mn(2+)-responsive metal transporter and pepO encoding a zinc metallopeptidase are not coordinately regulated.
The divergently transcribed Streptococcus parasanguis virulence-associated fimA operon encoding an Mn(2+)-responsive metal transporter and pepO encoding a zinc metallopeptidase are not coordinately regulated.
复制标题
编码Mn(2)响应性金属转运蛋白的发散转录的副血链球菌毒力相关的fimA操纵子和编码锌金属肽酶的pepO不受协调调节。
DOI：
10.1128/iai.70.10.5706-5714.2002
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发表时间：
2002
影响因子：
3.1
通讯作者：
Froeliger,EuniceH
中科院分区：
文献类型：
--
作者：
Oetjen,Joyce;Fives-Taylor,Paula;Froeliger,EuniceH
The study of how bacteria respond to and obtain divalent metal ions provides insight into the regulation of virulence factors in the host environment. Regulation of metal permease operons in gram-positive bacteria may involve the binding of metal-responsive repressors to palindromic domains in their control regions. TheStreptococcus parasanguis fimAoperon, which encodes an ATP-binding cassette (ABC) transporter system with sequence homology to the LraI family of metal transporters, possesses a palindromic regulatory region with high homology to that of theStreptococcus gordoniiScaR binding domain. Mapping of the promoter and regulatory regions offimAand the divergently transcribedpepOgene, which encodes a zinc metalloendopeptidase, indicated that their promoter and regulatory elements overlap.fimAhad one transcriptional start site, whereaspepOhad three. Analysis of truncated versions of thepepOpromoter suggested that all three transcriptional start sites are functional. Analysis of promoter activity under various environmental conditions indicated that thefimAoperon promoter and thepepOpromoter are not coordinately regulated. ThefimAoperon is responsive to changes in Mn2+concentration, but thepepOpromoter is not. AS. parasanguis fimAmutant showed a growth deficiency under conditions of limiting Mn2+. This deficiency was not alleviated by compensation with either Mg2+or Fe3+. Wild-typeS. parasanguiscould take up Mn2+and Fe3+, while thefimAmutant showed a marked reduction in this ability. These data suggested that FimA is a component of a metal transporter system capable of transporting both Mn2+and Fe3+. FimA expression itself was shown to be responsive to Mn2+concentration, but not to availability of Fe3+or Mg2+.
