Standalone cohesin as a molecular shuttle in cellulosome assembly

• Published in: FEBS letters Vol. 589; no. 14; pp. 1569 - 1576
• Main Authors: Voronov-Goldman, Milana, Yaniv, Oren, Gul, Ozgur, Yoffe, Hagar, Salama-Alber, Orly, Slutzki, Michal, Levy-Assaraf, Maly, Jindou, Sadanari, Shimon, Linda J.W., Borovok, Ilya, Bayer, Edward A., Lamed, Raphael, Frolow, Felix
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 22.06.2015
• Subjects: Amino Acid Sequence; Cell Cycle Proteins - chemistry; Cell Cycle Proteins - metabolism; Cellulose degradation; cellulose-binding protein; Cellulosomes - metabolism; Chromosomal Proteins, Non-Histone - chemistry; Chromosomal Proteins, Non-Histone - metabolism; Clostridium thermocellum; Coh; CohE; Cohesin; cohesin G; cohesin module of ScaE; Cohesins; Cohesin–dockerin complex; CohG; Crystallography, X-Ray; CttA; Doc; Dockerin; IPTG; isopropyl-1-thio-β-d-galactoside; Models, Molecular; Molecular Sequence Data; Rumen bacteria; Ruminococcus flavefaciens; Sca; scaffoldin; Sequence Homology, Amino Acid; Type III; X-dockerin modular dyad; XDoc; Dockerin; Cohesin–dockerin complex; Ruminococcus flavefaciens; CohE; XDoc; CohG; Sca; Ct; Type III; Rf; IPTG; Doc; Rumen bacteria; Cohesin; Coh; CttA; Cellulose degradation
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/j.febslet.2015.04.013

The cellulolytic bacterium Ruminococcus flavefaciens of the herbivore rumen produces an elaborate cellulosome system, anchored to the bacterial cell wall via the covalently bound scaffoldin ScaE. Dockerin-bearing scaffoldins also bind to an autonomous cohesin of unknown function, called cohesin G (CohG). Here, we demonstrate that CohG binds to the scaffoldin-borne dockerin in opposite orientation on a distinct site, relative to that of ScaE. Based on these structural data, we propose that the complexed dockerin is still available to bind ScaE on the cell surface. CohG may thus serve as a molecular shuttle for delivery of scaffoldins to the bacterial cell surface.