2j4m
From Proteopedia
DOUBLE DOCKERIN FROM PIROMYCES EQUI CEL45A
Overview
The assembly into supramolecular complexes of proteins having complementary activities is central to cellular function. One such complex of considerable biological and industrial significance is the plant cell wall-degrading apparatus of anaerobic microorganisms, termed the cellulosome. A central feature of bacterial cellulosomes is a large non-catalytic protein, the scaffoldin, which contains multiple cohesin domains. An array of digestive enzymes is incorporated into the cellulosome through the interaction of the dockerin domains, present in the catalytic subunits, with the cohesin domains that are present in the scaffoldin. By contrast, in anaerobic fungi, such as Piromyces equi, the dockerins of cellulosomal enzymes are often present in tandem copies; however, the identity of the cognate cohesin domains in these organisms is unclear, hindering further biotechnological development of the fungal cellulosome. Here, we characterise the solution structure and function of a double-dockerin construct from the P. equi endoglucanase Cel45A. We show that the two domains are connected by a flexible linker that is short enough to keep the binding sites of the two domains on adjacent surfaces, and allows the double-dockerin construct to bind more tightly to cellulosomes than a single domain and with greater coverage. The double dockerin binds to the GH3 beta-glucosidase component of the fungal cellulosome, which is thereby identified as a potential scaffoldin.
About this Structure
2J4M is a Single protein structure of sequence from Piromyces equi. Full crystallographic information is available from OCA.
Reference
Characterization of a double dockerin from the cellulosome of the anaerobic fungus Piromyces equi., Nagy T, Tunnicliffe RB, Higgins LD, Walters C, Gilbert HJ, Williamson MP, J Mol Biol. 2007 Oct 26;373(3):612-22. Epub 2007 Aug 19. PMID:17869267 Page seeded by OCA on Sun May 4 08:19:41 2008
