- Serine hydroxymethyltransferase
protein
Name=serine hydroxymethyltransferase 1 (soluble)
caption=
width=
HGNCid=10850
Symbol=SHMT1
AltSymbols=
EntrezGene=6470
OMIM=182144
RefSeq=NM_148918
UniProt=P34896
PDB=
ECnumber=
Chromosome=17
Arm=p
Band=11.2
LocusSupplementaryData=protein
Name=serine hydroxymethyltransferase 2 (mitochondrial)
caption=
width=
HGNCid=10852
Symbol=SHMT2
AltSymbols=SHMT
EntrezGene=6472
OMIM=138450
RefSeq=NM_005412
UniProt=P34897
PDB=
ECnumber=2.1.2.1
Chromosome=12
Arm=q
Band=12
LocusSupplementaryData=-q14Serine hydroxymethyltransferase (SHMT) is an enzyme (EC number|2.1.2.1) which plays an important role in cellular one-carbon pathways by catalyzing the reversible, simultaneous conversions of L-
serine toglycine (retro-aldol cleavage) and5,6,7,8-tetrahydrofolate to5,10-methylenetetrahydrofolate (hydrolysis). Rao, N.A., Ambili, M., Jala V.R., Subramanya, H.S. Savithri, H.S. 2003. Structure-function relationship in serine hydroxymethyltransferase. Biochimica et Biophysica Acta 1647: 24-29 ] This reaction provides the largest part of the one-carbon units available to the cell. Stover, P., Schirch, V. 1990 Serine hydroxymethyltransferase catalyzes the hydrolysis of 5,10-methylenyltetrahydrofolate to 5-formyltetrahydrofolate. Journal of Biological Chemistry 265(24): 14227-14233 ]Isoforms
Bacteria such as "
Escherichia coli " and "Bacillus stearothermophilus " have versions of this enzyme and there appear to be two isoforms of SHMT in mammals, one in thecytoplasm (cSHMT) and another in themitochondria (mSHMT). Plants may have an additional SHMT isoform withinchloroplast s [ Besson V., Nauburger, M., Rebeille, F., Douce, R. 1995. Evidence for three serine hydroxymethyltransferases in green leaf cells. Purification and characterization of the mitochondrial and chloroplastic isoforms. Plant physiol. biochem. 33: 665-673 ]Other reactions
As well as its primary role in folate metabolism, SHMT also catabolyzes other reactions that may be biologically significant, including the conversion of 5,10-methenyltetrahydrofolate to
10-formyltetrahydrofolate . When coupled with C1-tetrahydrofolate synthase and tetrahydropteroate, cSHMT also catalyzes the conversion of formate to serine.Role in Smith-Magenis syndrome
Smith-Magenis syndrome (SMS) is a rare disorder that manifests as a complex set of traits including facial abnormalities, unusual behaviors, and developmental delay. Elsea, S.H., Juyal, R.C., Jiralerspong, S., Finucane, B.M., Pandolfo, M., Greenberg, F., Baldini, A., Stover, P., Patel P.I. 1995. Haploinsufficiency of cytosolic serine hydroxymethyltransferase in the Smith-Magenis syndrome. Am. J. Hum. Genet. 57:1342-1350 ] It results from an interstital deletion within chromosome 17p11.2, including the cSHMT gene and a small study showed SHMT activity in SMS patients was ~50% of normal. Reduced SHMT would result in less glycine which could affect the nervous system by acting as an agonist to the NMDA receptor and this could be a mechanism behind SMS.References
External links
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