4UMS

The crystal structure of the seventh ScaB type I cohesin from Pseudobacteroides cellulosolvens

4UMS の概要

• エントリーDOI: 10.2210/pdb4ums/pdb
• 分子名称: CELLULOSOMAL ANCHORING SCAFFOLDIN B (2 entities in total)
• 機能のキーワード: structural protein, cellulosome, cohesins, dockerins, type i binding scaffoldin scab
• 由来する生物種: BACTEROIDES CELLULOSOLVENS
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 16958.14

構造登録者

Cameron, K.,Alves, V.D.,Ferreira, L.M.A.,Fontes, C.M.G.A.,Najmudin, S. (登録日: 2014-05-20, 公開日: 2015-05-06, 最終更新日: 2024-01-10)

主引用文献

Cameron, K.,Alves, V.D.,Bayer, E.A.,Gilbert, H.J.,Ferreira, L.M.A.,Fontes, C.M.G.A.,Najmudin, S.
Combined Crystal Structure of a Type-I Cohesin, Mutation and Affinity-Binding Studies Reveal Structural Determinants of Cohesin-Dockerin Specificity
J.Biol.Chem., 290:16215-, 2015

PubMed Abstract: Cohesin-dockerin interactions orchestrate the assembly of one of nature's most elaborate multienzyme complexes, the cellulosome. Cellulosomes are produced exclusively by anaerobic microbes and mediate highly efficient hydrolysis of plant structural polysaccharides, such as cellulose and hemicellulose. In the canonical model of cellulosome assembly, type I dockerin modules of the enzymes bind to reiterated type I cohesin modules of a primary scaffoldin. Each type I dockerin contains two highly conserved cohesin-binding sites, which confer quaternary flexibility to the multienzyme complex. The scaffoldin also bears a type II dockerin that anchors the entire complex to the cell surface by binding type II cohesins of anchoring scaffoldins. In Bacteroides cellulosolvens, however, the organization of the cohesin-dockerin types is reversed, whereby type II cohesin-dockerin pairs integrate the enzymes into the primary scaffoldin, and type I modules mediate cellulosome attachment to an anchoring scaffoldin. Here, we report the crystal structure of a type I cohesin from B. cellulosolvens anchoring scaffoldin ScaB to 1.84-Å resolution. The structure resembles other type I cohesins, and the putative dockerin-binding site, centered at β-strands 3, 5, and 6, is likely to be conserved in other B. cellulosolvens type I cohesins. Combined computational modeling, mutagenesis, and affinity-based binding studies revealed similar hydrogen-bonding networks between putative Ser/Asp recognition residues in the dockerin at positions 11/12 and 45/46, suggesting that a dual-binding mode is not exclusive to the integration of enzymes into primary cellulosomes but can also characterize polycellulosome assembly and cell-surface attachment. This general approach may provide valuable structural information of the cohesin-dockerin interface, in lieu of a definitive crystal structure.

PubMed: 25934389
DOI: 10.1074/JBC.M115.653303

実験手法

X-RAY DIFFRACTION (1.84 Å)