@article {pmid26958837,
	title = {Observing cellulose biosynthesis and membrane translocation in crystallo},
	journal = {Nature},
	volume = {531},
	number = {7594},
	year = {2016},
	note = {[DOI:\href{http://dx.doi.org/10.1038/nature16966}{10.1038/nature16966}] [PubMed:\href{http://www.ncbi.nlm.nih.gov/pubmed/26958837}{26958837}]},
	month = {Mar},
	pages = {329{\textendash}334},
	abstract = {<p>Many biopolymers, including polysaccharides, must be translocated across at least one membrane to reach their site of biological function. Cellulose is a linear glucose polymer synthesized and secreted by a membrane-integrated cellulose synthase. Here, in crystallo enzymology with the catalytically active bacterial cellulose synthase BcsA-BcsB complex reveals structural snapshots of a complete cellulose biosynthesis cycle, from substrate binding to polymer translocation. Substrate- and product-bound structures of BcsA provide the basis for substrate recognition and demonstrate the stepwise elongation of cellulose. Furthermore, the structural snapshots show that BcsA translocates cellulose via a ratcheting mechanism involving a \&$\#$39;finger helix\&$\#$39; that contacts the polymer\&$\#$39;s terminal glucose. Cooperating with BcsA\&$\#$39;s gating loop, the finger helix moves \&$\#$39;up\&$\#$39; and \&$\#$39;down\&$\#$39; in response to substrate binding and polymer elongation, respectively, thereby pushing the elongated polymer into BcsA\&$\#$39;s transmembrane channel. This mechanism is validated experimentally by tethering BcsA\&$\#$39;s finger helix, which inhibits polymer translocation but not elongation.</p>},
	doi = {10.1038/nature16966},
	url = {http://www.nature.com/nature/journal/v531/n7594/full/nature16966.html},
	author = {Morgan, J. L. and McNamara, J. T. and Fischer, M. and Rich, J. and Chen, H. M. and Withers, S. G. and Zimmer, J.}
}
