Identification and Molecular Analysis of PcsB, a Protein Required for Cell Wall Separation of Group B Streptococcus
Identification and Molecular Analysis of PcsB, a Protein Required for Cell Wall Separation of Group B Streptococcus
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B 族链球菌细胞壁分离所需蛋白质 PcsB 的鉴定和分子分析
DOI：
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发表时间：
2001
影响因子：
3.2
通讯作者：
G. S. Chhatwal
中科院分区：
文献类型：
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作者：
D. Reinscheid;B. Gottschalk;A. Schubert;B. Eikmanns;G. S. Chhatwal
B群链球菌（GBS）是新生儿细菌性败血症和脑膜炎的主要原因。对GBS临床分离株的培养上清液中的主要蛋白质进行N-末端测序，鉴定出约50 kDa的蛋白质，其可在所有27个测试的临床分离株中检测到。从GBS粘粒库中分离出相应的基因，命名为pcsB，随后进行测序。推导的PcsB多肽由447个氨基酸残基（Mr，46，754）组成，携带25个氨基酸的潜在N-末端信号肽序列，并且与来自不同生物体的未知功能的开放阅读框架和来自单核细胞增生李斯特菌的胞壁素水解酶P45显示出显著的相似性。北方印迹分析显示GBS中pcsB的转录组织为单顺反子。插入失活的pcsBin基因组的GBS导致突变株Sep 1表现出显着降低的生长速度相比，亲本GBS菌株，并表现出增加的敏感性渗透压和各种抗生素。GBS突变体Sep 1的电子显微镜分析显示，在丛生，细胞分离在几个平面，和多个分裂隔膜内的单细胞的增长。这些数据表明PcsB在GBS的细胞分裂和抗生素耐受性中起关键作用。
ABSTRACT Group B streptococcus (GBS) is the leading cause of bacterial sepsis and meningitis in neonates. N-terminal sequencing of major proteins in the culture supernatant of a clinical isolate of GBS identified a protein of about 50 kDa which could be detected in all of 27 clinical isolates tested. The corresponding gene, designatedpcsB, was isolated from a GBS cosmid library and subsequently sequenced. The deduced PcsB polypeptide consists of 447 amino acid residues (Mr, 46,754), carries a potential N-terminal signal peptide sequence of 25 amino acids, and shows significant similarity to open reading frames of unknown function from different organisms and to the murein hydrolase P45 from Listeria monocytogenes. Northern blot analysis revealed a monocistronic transcriptional organization forpcsB in GBS. Insertional inactivation of pcsBin the genome of GBS resulted in mutant strain Sep1 exhibiting a drastically reduced growth rate compared to the parental GBS strain and showing an increased susceptibility to osmotic pressure and to various antibiotics. Electron microscopic analysis of GBS mutant Sep1 revealed growth in clumps, cell separation in several planes, and multiple division septa within single cells. These data suggest a pivotal role of PcsB for cell division and antibiotic tolerance of GBS.
影响因子：
56.9
作者：
NIKAIDO, H
通讯作者：
NIKAIDO, H