Palacín Arantxa, Parro Víctor, Geukens Nick, Anné Jozef, Mellado Rafael P
Centro Nacional de Biotecnología, Campus de la Universidad Autónoma, Cantoblanco, 28049 Madrid, Spain.
J Bacteriol. 2002 Sep;184(17):4875-80. doi: 10.1128/JB.184.17.4875-4880.2002.
Most bacteria contain one type I signal peptidase (SPase) for cleavage of signal peptides from secreted proteins. The developmental complex bacterium Streptomyces lividans has the ability to produce and secrete a significant amount of proteins and has four different type I signal peptidases genes (sipW, sipX, sipY, and sipZ) unusually clustered in its chromosome. Functional analysis of the four SPases was carried out by phenotypical and molecular characterization of the different individual sip mutants. None of the sip genes seemed to be essential for bacterial growth. Analysis of total extracellular proteins indicated that SipY is likely to be the major S. lividans SPase, since the sipY mutant strain is highly deficient in overall protein secretion and extracellular protease production, showing a delayed sporulation phenotype when cultured in solid medium.
大多数细菌含有一种I型信号肽酶(SPase),用于从分泌蛋白中切割信号肽。发育复杂的细菌淡紫链霉菌有能力产生和分泌大量蛋白质,并且在其染色体上有四个不同的I型信号肽酶基因(sipW、sipX、sipY和sipZ)异常聚集。通过对不同单个sip突变体进行表型和分子特征分析,对这四种SPase进行了功能分析。似乎没有一个sip基因对细菌生长是必需的。对总细胞外蛋白的分析表明,SipY可能是淡紫链霉菌的主要SPase,因为sipY突变体菌株在总体蛋白分泌和细胞外蛋白酶产生方面高度缺陷,在固体培养基中培养时表现出延迟的孢子形成表型。