Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
13
pubmed:dateCreated
2011-3-30
pubmed:databankReference
pubmed:abstractText
Clostridium thermocellum is a well-characterized cellulose-degrading microorganism. The genome sequence of C. thermocellum encodes a number of proteins that contain type I dockerin domains, which implies that they are components of the cellulose-degrading apparatus, but display no significant sequence similarity to known plant cell wall-degrading enzymes. Here, we report the biochemical properties and crystal structure of one of these proteins, designated CtCel124. The protein was shown to be an endo-acting cellulase that displays a single displacement mechanism and acts in synergy with Cel48S, the major cellulosomal exo-cellulase. The crystal structure of CtCel124 in complex with two cellotriose molecules, determined to 1.5 ?, displays a superhelical fold in which a constellation of ?-helices encircle a central helix that houses the catalytic apparatus. The catalytic acid, Glu96, is located at the C-terminus of the central helix, but there is no candidate catalytic base. The substrate-binding cleft can be divided into two discrete topographical domains in which the bound cellotriose molecules display twisted and linear conformations, respectively, suggesting that the enzyme may target the interface between crystalline and disordered regions of cellulose.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1091-6490
pubmed:author
pubmed:issnType
Electronic
pubmed:day
29
pubmed:volume
108
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5237-42
pubmed:dateRevised
2011-9-30
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
Structural insights into a unique cellulase fold and mechanism of cellulose hydrolysis.
pubmed:affiliation
Centro de Investigação Interdisciplinar em Sanidade Animal, Faculdade de Medicina Veterinária, Pólo Universitário do Alto da Ajuda, Avenida da Universidade Técnica, 1300-477 Lisbon, Portugal.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't