Linked Life Data

10985769

Source:http://linkedlifedata.com/resource/pubmed/id/10985769

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
37
pubmed:dateCreated
2000-10-19
pubmed:databankReference
pubmed:abstractText
Cellulase Cel48F from Clostridium cellulolyticum was described as a processive endo-cellulase. The active site is composed of a 25 A long tunnel which is followed by an open cleft. During the processive action, the cellulose substrate has to slide through the tunnel to continuously supply the leaving group site with sugar residues after the catalytic cleavage. To study this processive action in the tunnel, the native catalytic module of Cel48F and the inactive mutant E55Q, have been cocrystallized with cellobiitol, two thio-oligosaccharide inhibitors (PIPS-IG3 and IG4) and the cello-oligosaccharides cellobiose, -tetraose and -hexaose. Seven sub-sites in the tunnel section of the active center could be identified and three of the four previously reported sub-sites in the open cleft section were reconfirmed. The sub-sites observed for the thio-oligosaccharide inhibitors and oligosaccharides, respectively, were located at two different positions in the tunnel corresponding to a shift in the chain direction of about a half sugar subunit. These two positions have different patterns of stacking interactions with aromatic residues present in the tunnel. Multiple patterns are not observed in nonprocessive endo-cellulases, where only one sugar position is favored by aromatic stacking. It is therefore proposed that the aromatic residues serve as lubricating agents to reduce the sliding barrier in the processive action.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
19
pubmed:volume
39
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
11238-46
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Crystal structures of the cellulase Cel48F in complex with inhibitors and substrates give insights into its processive action.
pubmed:affiliation
Institut de Biologie et Chimie des Protéines, Laboratoire de Bio-Cristallographie, Centre National de la Recherche Scientifique UMR 5086 and Université Claude Bernard Lyon I, 7 passage du Vercors, 69367 Lyon Cedex 07, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't