Linked Life Data

17444657

Source:http://linkedlifedata.com/resource/pubmed/id/17444657

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
19
pubmed:dateCreated
2007-5-9
pubmed:databankReference
pubmed:abstractText
In the prokaryote Acholeplasma laidlawii, membrane bilayer properties are sensed and regulated by two interface glycosyltransferases (GTs), synthesizing major nonbilayer- (alMGS GT) and bilayer-prone glucolipids. These enzymes are of similar structure, as many soluble GTs, but are sensitive to lipid charge and curvature stress properties. Multivariate and bioinformatic sequence analyses show that such interface enzymes, in relation to soluble ones of similar fold, are characterized by high cationic charge, certain distances between small and cationic amino acids, and by amphipathic helices. Varying surface contents of Lys/Arg pairs and Trp indicate different membrane-binding subclasses. A predicted potential (cationic) binding helix from alMGS was structurally verified by solution NMR and CD. The helix conformation was induced by a zwitterionic as well as anionic lipid environment, and the peptide was confined to the bilayer interface. Bilayer affinity of the peptide, analyzed by surface plasmon resonance, was higher than that for soluble membrane-seeking proteins/peptides and rose with anionic lipid content. Interface intercalation was supported by phase equilibria in membrane lipid mixtures, analyzed by 31P NMR and DSC. An analogous, potentially binding helix has a similar location in the structurally determined Escherichia coli cell wall precursor GT MurG. These two helices have little sequence conservation in alMGS and MurG homologues but maintain their amphipathic character. The evolutionary modification of the alMGS binding helix and its location close to the acceptor substrate site imply a functional importance in enzyme catalysis, potentially providing a mechanism by which glycolipid synthesis will be sensitive to membrane surface charge and intrinsic curvature strain.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
46
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5664-77
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
High cationic charge and bilayer interface-binding helices in a regulatory lipid glycosyltransferase.
pubmed:affiliation
Center for Biomembrane Research, Department of Biochemistry and Biophysics, Stockholm University, SE-10691 Stockholm, Sweden.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't