1DAQ

SOLUTION STRUCTURE OF THE TYPE I DOCKERIN DOMAIN FROM THE CLOSTRIDIUM THERMOCELLUM CELLULOSOME (MINIMIZED AVERAGE STRUCTURE)

Summary for 1DAQ

• Entry DOI: 10.2210/pdb1daq/pdb
• Related: 1DAV
• NMR Information: BMRB: 4524
• Descriptor: ENDOGLUCANASE SS, CALCIUM ION (2 entities in total)
• Functional Keywords: cellulose degradation, cellulosome, calcium-binding, hydrolase
• Biological source: Clostridium thermocellum
• Total number of polymer chains: 1
• Total formula weight: 7938.93

Authors

Lytle, B.L.,Volkman, B.F.,Westler, W.M.,Heckman, M.P.,Wu, J.H.D. (deposition date: 1999-10-31, release date: 2001-04-04, Last modification date: 2024-05-22)

Primary citation

Lytle, B.L.,Volkman, B.F.,Westler, W.M.,Heckman, M.P.,Wu, J.H.
Solution structure of a type I dockerin domain, a novel prokaryotic, extracellular calcium-binding domain.
J.Mol.Biol., 307:745-753, 2001

PubMed Abstract: The type I dockerin domain is responsible for incorporating its associated glycosyl hydrolase into the bacterial cellulosome, a multienzyme cellulolytic complex, via its interaction with a receptor domain (cohesin domain) of the cellulosomal scaffolding subunit. The highly conserved dockerin domain is characterized by two Ca(2+)-binding sites with sequence similarity to the EF-hand motif. Here, we present the three-dimensional solution structure of the 69 residue dockerin domain of Clostridium thermocellum cellobiohydrolase CelS. Torsion angle dynamics calculations utilizing a total of 728 NOE-derived distance constraints and 79 torsion angle restraints yielded an ensemble of 20 structures with an average backbone r.m.s.d. for residues 5 to 29 and 32 to 66 of 0.54 A from the mean structure. The structure consists of two Ca(2+)-binding loop-helix motifs connected by a linker; the E helices entering each loop of the classical EF-hand motif are absent from the dockerin domain. Each dockerin Ca(2+)-binding subdomain is stabilized by a cluster of buried hydrophobic side-chains. Structural comparisons reveal that, in its non-complexed state, the dockerin fold displays a dramatic departure from that of Ca(2+)-bound EF-hand domains. A putative cohesin-binding surface, comprised of conserved hydrophobic and basic residues, is proposed, providing new insight into cellulosome assembly.

PubMed: 11273698
DOI: 10.1006/jmbi.2001.4522

Experimental method

SOLUTION NMR