Salamitou S, Tokatlidis K, Béguin P, Aubert J P
Unité de Physiologie Cellulaire and URA 1300 CNRS, Département des Biotechnologies, Institut Pasteur, Paris, France.
FEBS Lett. 1992 Jun 8;304(1):89-92. doi: 10.1016/0014-5793(92)80595-8.
Fragments of the 250 kDa S1 subunit of the Clostridium thermocellum cellulosome were obtained by protease-induced or spontaneous degradation. All detectable fragments, down to a mass of about 30 kDa, retained the ability to bind to 125I-labelled endoglucanase CelD, one of the catalytic subunits of the cellulosome. Several fragments were able to bind both to cellulose and to CelD. However, some fragments that could still bind to CelD did not have the ability to bind to cellulose. Therefore, S1, a putative scaffolding protein of the cellulosome, is likely to carry two separate types of domains, one of which binds to cellulose, while the other type binds to the various catalytic subunits of the complex.
通过蛋白酶诱导或自发降解获得了嗜热栖热放线菌纤维小体250 kDa S1亚基的片段。所有可检测到的片段，质量低至约30 kDa，都保留了与125I标记的内切葡聚糖酶CelD结合的能力，CelD是纤维小体的催化亚基之一。几个片段能够同时结合纤维素和CelD。然而，一些仍能与CelD结合的片段却没有结合纤维素的能力。因此，S1作为纤维小体的一种假定支架蛋白，可能携带两种不同类型的结构域，其中一种与纤维素结合，而另一种与该复合物的各种催化亚基结合。
