Schizosaccharomyces pombe och1(+) encodes alpha-1,6-mannosyltransferase that is involved in outer chain elongation of N-linked oligosaccharides.
The fission yeast Schizosaccharomyces pombe attaches an outer chain containing mannose and galactose to the N-linked oligosaccharides on many of its glycoproteins. We identified an S. pombe och1 mutant that did not synthesize the outer chains on acid phosphatase. The S. pombe och1(+) gene was a functional homolog of Saccharomyces cerevisiae OCH1, and its gene product (SpOch1p) incorporated alpha-1,6-linked mannose into pyridylaminated Man(9)GlcNAc(2), indicating that och1(+) encodes an alpha-1,6-mannosyltransferase. Our results indicate that SpOch1p is a key enzyme of outer chain elongation. The substrate specificity of SpOch1p was different from that of S. cerevisiae OCH1 gene product (ScOch1p), suggesting that SpOch1p may have a wider substrate specificity than that of ScOch1p.
National Institute of Bioscience and Human Technology, Higashi, Tsukuba, Japan.
T
T
Yoko-o
K
K
Tsukahara
T
T
Watanabe
N
N
Hata-Sugi
K
K
Yoshimatsu
T
T
Nagasu
Y
Y
Jigami
D000595:Amino Acid Sequence; D002240:Carbohydrate Sequence; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism; D008364:Mannosyltransferases / Q000235:genetics* / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000737:chemistry / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology; D029701:Saccharomyces cerevisiae Proteins; D012568:Schizosaccharomyces / Q000201:enzymology / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D013329:Structure-Activity Relationship; D013379:Substrate Specificity
D005656:Fungal Proteins; D008562:Membrane Glycoproteins; C075636:OCH1 protein, S cerevisiae; D009844:Oligosaccharides; D029701:Saccharomyces cerevisiae Proteins; D008364:Mannosyltransferases; C058478:alpha 1,6-mannosyltransferase