STRUCTURE OF SACCHAROMYCES-CEREVISIAE ALPHA-AGGLUTININ - EVIDENCE FOR A YEAST-CELL WALL PROTEIN WITH MULTIPLE IMMUNOGLOBULIN-LIKE DOMAINS WITH ATYPICAL DISULFIDES
STRUCTURE OF SACCHAROMYCES-CEREVISIAE ALPHA-AGGLUTININ - EVIDENCE FOR A YEAST-CELL WALL PROTEIN WITH MULTIPLE IMMUNOGLOBULIN-LIKE DOMAINS WITH ATYPICAL DISULFIDES
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DOI：
10.1074/jbc.270.44.26168
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发表时间：
1995-11-03
影响因子：
4.8
通讯作者：
LIPKE, PN
中科院分区：
文献类型：
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作者：
CHEN, MH;SHEN, ZM;LIPKE, PN
酿酒酵母α-凝集素是一种细胞壁相关蛋白，在交配过程中介导细胞间的相互作用。虽然成熟蛋白包括约610个残基，但NH2末端的一半足以与其配体α-凝集素-α-凝集素(20-351)结合，该蛋白的一个完全活性片段已被纯化和分析。圆二色谱结合序列比对表明，α-凝集素(20-351)由三个免疫球蛋白可变结构域组成：结构域I，残基20-104；结构域IL，残基105-199；结构域ID，残基200-326。多肽测序数据确定了α-凝集素(20-351)中二硫键的排列。半胱氨酸(97)与半胱氨酸(114)成二硫键，在结构域I和结构域II之间形成域间键。半胱氨酸(202)与半胱氨酸(300)成键，在结构域III的A和F链之间形成非典型的二硫键，半胱氨酸(227)和半胱氨酸(256)具有游离的巯基。测序还表明，序列为ASN-Xaa-Thr的三个潜在N-糖基化位点中至少有两个是糖基化的。三个Asn-Xaa-Ser序列中至少有一个没有糖基化。没有NH2端到Ser(282)的残基是O-糖基化的，而Ser(282)和该位置的所有羟基氨基酸残基COOH-端都被修饰了。因此，O-糖基化的丝氨酸和苏氨酸残基聚集在结构域III的COOH末端区域。O-糖基化继续进入富含Sen/Thr的序列，该序列从结构域III延伸到全长蛋白质的COOH-末端。
alpha-Agglutinin of Saccharomyces cerevisiae is a cell wall-associated protein that mediates cell interaction in mating. Although the mature protein includes about 610 residues, the NH2-terminal half of the protein is sufficient for binding to its ligand alpha-agglutinin alpha-Agglutinin(20-351), a fully active fragment of the protein, has been purified and analyzed. Circular dichroism spectroscopy, together with sequence alignments, suggest that alpha-agglutinin(20-351) consists of three immunoglobulin variable-like domains: domain I, residues 20-104; domain IL, residues 105-199; and domain ID. residues 200-326. Peptide sequencing data established the arrangement of the disulfide bonds in alpha-agglutinin(20-351). Cys(97) is disulfide-bonded to Cys(114), forming an interdomain bond between domains I and II. Cys(202) is bonded to Cys(300), in an atypical intradomain disulfide bond between the A and F strands of domain III, Cys(227) and Cys(256) have free sulfhydryls. Sequencing also showed that at least two of three potential N-glycosylation sites with sequence Asn-Xaa-Thr are glycosylated. At least one of three Asn-Xaa-Ser sequences is not glycosylated. No residues NH2-terminal to Ser(282) were O-glycosylated, whereas Ser(282), and all hydroxy amino acid residues COOH-terminal to this position were modified. Therefore O-glycosylated Ser and Thr residues cluster in the COOH-terminal region of domain Iii. and the O-glycosylation continues into a Sen/Thr-rich sequence that extends from domain III to the COOH-terminal of the full-length protein.