Amino acid distributions around O-linked glycosylation sites.
To study the sequence requirements for addition of O-linked N-acetylgalactosamine to proteins, amino acid distributions around 174 O-glycosylation sites were compared with distributions around non-glycosylated sites. In comparison with non-glycosylated serine and threonine residues, the most prominent feature in the vicinity of O-glycosylated sites is a significantly increased frequency of proline residues, especially at positions -1 and +3 relative to the glycosylated residues. Alanine, serine and threonine are also significantly increased. The high serine and threonine content of O-glycosylated regions is due to the presence of clusters of several closely spaced glycosylated hydroxy amino acids in many O-glycosylated proteins. Such clusters can be predicted from the primary sequence in some cases, but there is no apparent possibility of predicting isolated O-glycosylation sites from primary sequence data.
Wilson
I B
IB
Department of Biochemistry, University of Oxford, U.K.
Gavel
Y
Y
von Heijne
G
G
D000116:Acetylgalactosamine; D000595:Amino Acid Sequence; D000818:Animals; D016208:Databases, Factual; D006023:Glycoproteins / Q000737:chemistry*; D006031:Glycosylation; D006801:Humans; D012689:Sequence Homology, Nucleic Acid
D006023:Glycoproteins; D000116:Acetylgalactosamine