离解的cellulosome thermocellum梭状芽胞杆菌的乙二胺四乙酸发生与trucated多肽的形成。
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崔SK, Ljungdahl LG
离解的cellulosome thermocellum梭状芽胞杆菌的乙二胺四乙酸发生与trucated多肽的形成。
生物化学。1996年4月16日,35 (15):4897 - 905。
- PubMed ID
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8664281 (在PubMed]
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梭状芽胞杆菌的cellulosome thermocellum JW20由14日至26日不同的多肽由钠十二烷基sulfate-polyacrylamide凝胶电泳。完整的cellulosomes水解纤维素晶体Ca2 +的存在和硫醇。这个活动被乙二胺四乙酸(EDTA)。Ca纳入cellulosome紧密地绑定和演示了使用45 Ca添加到生长介质。在孵化50毫米三羟甲基氨基甲烷(pH值7.5)液,0.1 M氯化钠和5毫米EDTA在37摄氏度,Ca是cellulosome释放,分解成多肽。cellulosomal多肽的sds - page模式非常不同的EDTA处理后未经处理的cellulosomes相比,这种模式。多肽乐队对应的分子质量160,98,76,91和54 kDa消失,和群众的新乐队150年,132年,91年,71年,57岁和46 kDa出现。氨基端分析98年、76年、91年和71 kDa多肽显示,91年和71年kDa多肽截断产品98和76 kDa的多肽,分别。76和71 kDa多肽对应于塞尔(Wang w·K。Kruus K。&吴,j·h·d·j . Bacteriol(1993)。175年,1293 - 1302]。 The 71 kDa polypeptide is formed from the 76 kDa polypeptide during the EDTA treatment, by a cleavage that occurs at asparagine residue 681. It involves the removal of 60 amino acid residues from the C-terminal end. All catalytic subunits so far characterized contain an asparagine residue corresponding to residue 681 of CelS. This residue is part of the conserved duplicated region found in catalytically active subunits, and it is postulated that several of these subunits also are truncated by the EDTA treatment. The polypeptides truncated by the EDTA treatment reduced Ca binding capacities compared to their native subunits, indicating a Ca-binding site within the conserved duplicated region. This region has been implicated in the binding of the catalytic peptides to the scaffolding polypeptide CipA, which is a structural protein of the cellulosome and has a strong affinity for calcium.