Hsu T, Minion F C
Department of Microbiology, Immunology and Preventive Medicine, Veterinary Medical Research Institute, Iowa State University, Ames, IA 50011, USA.
Gene. 1998 Jul 3;214(1-2):13-23. doi: 10.1016/s0378-1119(98)00247-9.
Mycoplasma hyopneumoniae causes an economically significant respiratory disease of swine called Enzootic Pneumonia. The disease process is initiated by adherence of M. hyopneumoniae to the cilia of swine respiratory epithelium through an interaction involving P97, a surface-associated protein, and cilia-specific receptors. Binding specificity is associated with a repeat region located near the C-terminus of the P97 protein. Further analysis of the DNA sequences surrounding the P97 structural gene revealed an operon composed of two ORFs, P97 and one coding for a 102.3-kDa protein designated P102. Hybridization analysis and subcloning experiments showed that the P97 adhesin-encoding gene was present as a single copy in the M. hyopneumoniae chromosome. P102 sequences, however, were found on four distinct chromosomal fragments, suggesting that multiple copies of P102 were present in the chromosome. One of these clones was identified by screening the genomic library with swine convalescent sera showing that P102 is expressed in vivo during M. hyopneumoniae infections. All copies of P102 were mapped to a single chromosomal region comprising approximately 13% of the genome (140kb), although the exact distance between the copies is not known. The function of P102 is also not known, but the translated sequence shows a prominent transmembrane domain, suggesting that it may be a surface protein.
猪肺炎支原体可引发一种在经济上具有重要意义的猪呼吸道疾病，称为地方性肺炎。疾病过程始于猪肺炎支原体通过一种涉及表面相关蛋白P97和纤毛特异性受体的相互作用，黏附于猪呼吸道上皮细胞的纤毛。结合特异性与位于P97蛋白C末端附近的一个重复区域相关。对P97结构基因周围DNA序列的进一步分析揭示了一个由两个开放阅读框（ORF）组成的操纵子，即P97和一个编码102.3 kDa蛋白（命名为P102）的基因。杂交分析和亚克隆实验表明，编码P97黏附素的基因在猪肺炎支原体染色体中以单拷贝形式存在。然而，在四个不同的染色体片段上发现了P102序列，这表明染色体中存在多个P102拷贝。通过用猪恢复期血清筛选基因组文库鉴定出其中一个克隆，表明P102在猪肺炎支原体感染期间在体内表达。尽管各拷贝之间的确切距离尚不清楚，但所有P102拷贝都被定位到一个单一的染色体区域，该区域约占基因组的13%（140kb）。P102的功能也尚不清楚，但其翻译后的序列显示出一个显著的跨膜结构域，这表明它可能是一种表面蛋白。
