Linked Life Data

19564159

Source:http://linkedlifedata.com/resource/pubmed/id/19564159

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2009-10-7
pubmed:abstractText
Serine palmitoyltransferase (SPT) is a key enzyme of sphingolipid biosynthesis and catalyses the pyridoxal 5'-phosphate (PLP)-dependent decarboxylative condensation reaction of l-serine with palmitoyl-CoA to generate 3-ketodihydrosphingosine. The crystal structure of SPT from Sphingobacterium multivorum GTC97 complexed with l-serine was determined at 2.3 A resolution. The electron density map showed the Schiff base formation between l-serine and PLP in the crystal. Because of the hydrogen bond formation with His138, the orientation of the Calpha-H bond of the PLP-l-serine aldimine was not perpendicular to the PLP-Schiff base plane. This conformation is unfavourable for the alpha-proton abstraction by Lys244 and the reaction is expected to stop at the PLP-l-serine aldimine. Structural modelling of the following intermediates indicated that His138 changes its hydrogen bond partner from the carboxyl group of l-serine to the carbonyl group of palmitoyl-CoA upon the binding of palmitoyl-CoA, making the l-serine Calpha-H bond perpendicular to the PLP-Schiff base plane. These crystal and model structures well explained the observations on bacterial SPTs that the alpha-deprotonation of l-serine occurs only in the presence of palmitoyl-CoA. This study provides the structural evidence that directly supports our proposed mechanism of the substrate synergism in the SPT reaction.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
1756-2651
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
146
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
549-62
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Structural insights into the enzymatic mechanism of serine palmitoyltransferase from Sphingobacterium multivorum.
pubmed:affiliation
Department of Biochemistry, Osaka Medical College, Takatsuki, Osaka 569-8686, Japan. ikushiro@art.osaka-med.ac.jp
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't