Discovery of sarcosine dimethylglycine methyltransferase from Galdieria sulphuraria.
An enzyme with sarcosine dimethylglycine methyltransferase (SDMT) activity has been identified in the thermophilic eukaryote, Galdieria sulphuraria. The crystal structure of the enzyme, solved to a resolution of 1.95 A, revealed a fold highly similar to that of mycolic acid synthases. The kcat and apparent K(M) values were 64.3 min(-1) and 2.0 mM for sarcosine and 85.6 min(-1) and 2.8 mM for dimethylglycine, respectively. Apparent K(M) values of S-adenosylmethionine were 144 and 150 microM for sarcosine and dimethylglycine, respectively, and the enzyme melting temperature was 61.1 degrees C. Modeling of cofactor binding in the active site based on the structure of methoxy mycolic acid synthase 2 revealed a number of conserved interactions within the active site.
McCoy
Jason G
JG
Center for Eukaryotic Structural Genomics and Department of Biochemistry, University of Wisconsin, Madison, WI 53706, USA.
Bailey
Lucas J
LJ
Ng
Yi Han
YH
Bingman
Craig A
CA
Wrobel
Russell
R
Weber
Andreas P M
AP
Fox
Brian G
BG
Phillips
George N
GN
D020418:Algal Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D018360:Crystallography, X-Ray; D004795:Enzyme Stability; D007700:Kinetics; D008780:Methyltransferases / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D017510:Protein Folding; D017434:Protein Structure, Tertiary; D000461:Rhodophyta / Q000201:enzymology*; D012521:Sarcosine / Q000031:analogs & derivatives* / Q000378:metabolism*; D016415:Sequence Alignment; D013379:Substrate Specificity; D013696:Temperature
D020418:Algal Proteins; C025138:dimethylglycine; D008780:Methyltransferases; D012521:Sarcosine