The adherence-associated lipoprotein P100, encoded by an opp operon structure, functions as the oligopeptide-binding domain OppA of a putative oligopeptide transport system in Mycoplasma hominis
The adherence-associated lipoprotein P100, encoded by an opp operon structure, functions as the oligopeptide-binding domain OppA of a putative oligopeptide transport system in Mycoplasma hominis
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DOI：
10.1128/jb.181.16.4873-4878.1999
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发表时间：
1999-08-01
影响因子：
3.2
通讯作者：
Hadding, U
中科院分区：
文献类型：
--
作者：
Henrich, B;Hopfe, M;Hadding, U
人型支原体是一种无细胞壁的原核生物，已表明其通过一种100kDa的膜蛋白（P100）参与而具有细胞黏附性。为了鉴定编码P100的基因，对P100的肽段进行了部分测序，以便合成适合作为检测P100基因探针的P100特异性寡核苷酸。通过这种策略，我们在携带P100基因的人型支原体PEG中鉴定出一个约10.4kb的基因组区域。对完整推导的蛋白质序列的分析表明，P100作为一种前脂蛋白表达，其N端区域具有肽结合蛋白共有的结构，C端区域具有ATP或GTP结合的P环结构。在P100基因的下游，定位了另外四个可能编码活性转运系统四个核心结构域（OppBCDF）的开放阅读框。在Northern杂交和逆转录 - PCR分析中证明了P100基因和oppBCDF在转录活性操纵子结构中的组织形式，因为所有基因特异性探针都检测到一种9.5kb的共同RNA。引物延伸分析显示转录起始位点位于P100基因编码甲硫氨酸的ATG上游323个核苷酸处。通过荧光光谱法证实了P100蛋白的肽结合特性，并有力地表明介导细胞黏附的脂蛋白P100代表OppA，即人型支原体中一种肽转运系统的底物结合结构域。
Mycoplasma hominis, a cell-wail-less prokaryote,was shown to be cytoadherent by the participation of a 100-kDa membrane protein (P100), To identify the gene encoding P100, peptides of P100 were partially sequenced to enable the synthesis of P100-specific oligonucleotides suitable as probes for the detection of the P100 gene. With this strategy, we identified a genomic region of about 10.4 kb in M, hominis PEG carrying the P100 gene. Analysis of the complete deduced protein sequence suggests that P100 is expressed as a prelipoprotein with a structure in the N-terminal region common to peptide-binding proteins and an ATP- or GTP-binding P-loop structure in the C-terminal region. Downstream of the P100 gene, an additional four open reading frames putatively encoding the four core domains of an active transport system, OppBCDF, were localized. The organization of the P100 gene and oppBCDF; in a transcriptionally active operon structure was demonstrated in Northern blot and reverse transcription-PCR analyses, as all gene-specific probes detected a common RNA of 9.5 kb. Primer extension analysis revealed that the transcriptional initiation site was localized 323 nucleotides upstream of the methionine-encoding ATG of the P100 gene. The peptide-binding character of the P100 protein aas confirmed by fluorescence spectroscopy and strongly suggests that the cytoadherence-mediating lipoprotein P100 represents OppA, the substrate-binding domain of a peptide transport system in M, hominis.