Nucleotide sequence of the G protein gene of human respiratory syncytial virus reveals an unusual type of viral membrane protein.
Nucleotide sequence of the G protein gene of human respiratory syncytial virus reveals an unusual type of viral membrane protein.
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DOI：
10.1073/pnas.82.12.4075
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发表时间：
1985-06
影响因子：
11.1
通讯作者：
G. Wertz;P. Collins;Yung;Huang;C. Gruber;S. Levine;L. Ball
中科院分区：
文献类型：
--
作者：
G. Wertz;P. Collins;Yung;Huang;C. Gruber;S. Levine;L. Ball
人类呼吸道合胞体 (RS) 病毒的主要表面糖蛋白 (G) 的成熟 Mr 估计为 84,000-90,000。在从 RS 病毒 mRNA 制备的 cDNA 克隆文库中，我们鉴定了与编码 Mr 36,000 多肽的信息杂交的克隆，该多肽经抗 G 抗血清特异性免疫沉淀。 G蛋白主链的氨基酸序列通过几个cDNA克隆的核苷酸序列分析来确定。它包含多种结构特征，使其在已知的病毒糖蛋白中独一无二。 G mRNA 长 918 个核苷酸，包含一个主要开放阅读框，编码具有 298 个氨基酸残基的多肽，Mr 为 32,587，这一发现与 G mRNA 体外翻译产物的 Mr 36,000 估计一致。这表明成熟糖蛋白50%以上的分子量可能由碳水化合物贡献。 G 的糖基化很大程度上抵抗衣霉素（一种 N-连接寡糖附着的抑制剂），表明大多数碳水化合物残基是通过 O-糖苷键附着的。据此，丝氨酸和苏氨酸残基（O-连接寡糖的受体位点）占总氨基酸组成的30.6%。 N-连接寡糖还有四个潜在的受体位点。该氨基酸序列缺乏NH2末端疏水信号序列和COOH末端疏水区域。相反，强疏水性区域位于氨基酸残基38和66之间。该区域既可以充当通过膜插入新生多肽的信号，也可以充当膜锚定位点。
The major surface glycoprotein (G) of human respiratory syncytial (RS) virus has an estimated mature Mr of 84,000-90,000. Among a library of cDNA clones prepared from RS virus mRNAs, we identified clones that hybridized to a message that encoded a Mr 36,000 polypeptide that was specifically immunoprecipitated with anti-G antiserum. The amino acid sequence of the G protein backbone was determined by nucleotide sequence analysis of several of the cDNA clones. It contains a combination of structural features that make it unique among the known viral glycoproteins. The G mRNA is 918 nucleotides long and contains a single major open reading frame that encodes a polypeptide having 298 amino acid residues with a Mr of 32,587, a finding consistent with the Mr 36,000 estimate for the in vitro translation product of the G mRNA. This suggests that greater than 50% of the molecular weight of the mature glycoprotein may be contributed by carbohydrate. Glycosylation of G is largely resistant to tunicamycin, an inhibitor of the attachment of N-linked oligosaccharides, suggesting that the majority of the carbohydrate residues are attached via O-glycosidic bonds. In accordance with this, serine and threonine residues, the acceptor sites for O-linked oligosaccharides, comprise 30.6% of the total amino acid composition. There are also four potential acceptor sites for N-linked oligosaccharides. The amino acid sequence lacks both an NH2-terminal hydrophobic signal sequence and a COOH-terminal hydrophobic region. Instead, a strongly hydrophobic region is located between amino acid residues 38 and 66. This region may serve as both the signal to insert the nascent polypeptide through the membrane and as the membrane anchor site.