...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of bacteriology >Sequence and structure of the yeast galactose transporter.
【24h】

Sequence and structure of the yeast galactose transporter.

机译：酵母半乳糖转运蛋白的序列和结构。

获取原文
   

获取外文期刊封面封底 >>

       
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The previously cloned GAL2 gene of the Saccharomyces cerevisiae galactose transporter has been sequenced. The nucleotide sequence predicts a protein with 574 amino acids (Mr, 63,789). Hydropathy plots suggest that there are 12 membrane-spanning segments. The galactose transporter shows both sequence and structural homology with a superfamily of sugar transporters which includes the human HepG2-erythrocyte and fetal muscle glucose transporters, the rat brain and liver glucose transporters, the Escherichia coli xylose and arabinose permeases, and the S. cerevisiae glucose, maltose, and galactose transporters. Sequence and structural motifs at the N-terminal and C-terminal regions of the proteins support the view that the genes of this superfamily arose by duplication of a common ancestral gene. In addition to the sequence homology and the presence of the 12 membrane-spanning segments, the members of the superfamily show characteristic lengths and distributions of the charged, hydrophilic connecting loops. There is indirect evidence that the transporter is an N-glycoprotein. However, its only N-glycosylation site occurs in a charged, hydrophilic segment. This could mean that this segment is part of a hydrophilic channel in the membrane. The transporter has a substrate site for the cyclic AMP-dependent protein kinase which may be a target of catabolite inactivation. The transporter lacks a strong sequence enriched for proline (P), glutamate (E), aspartate, serine (S), and threonine (T) and flanked by basic amino acids (PEST sequence) even though it has a short half-life. Mechanisms for converting the poor PEST to a possible PEST sequence are considered. Like the other members of the superfamily, the galactose transporter lacks a signal sequence.
机译：已经对酿酒酵母半乳糖转运蛋白的先前克隆的GAL2基因进行了测序。核苷酸序列可预测具有574个氨基酸的蛋白质（Mr，63,789）。亲水性图表明有12个跨膜段。半乳糖转运蛋白显示与糖转运蛋白超家族的序列和结构同源性，其中包括人类HepG2-红细胞和胎儿肌肉葡萄糖转运蛋白，大鼠脑和肝葡萄糖转运蛋白，大肠杆菌木糖和阿拉伯糖通透酶以及酿酒酵母葡萄糖。 ，麦芽糖和半乳糖转运蛋白。蛋白质N端和C端区域的序列和结构基序支持以下观点：该超家族的基因是通过共同祖先基因的复制而产生的。除了序列同源性和存在12个跨膜片段外，超家族成员还显示了带电亲水连接环的特征长度和分布。有间接证据表明转运蛋白是一种N-糖蛋白。但是，它唯一的N-糖基化位点出现在带电的亲水链段中。这可能意味着该片段是膜中亲水通道的一部分。该转运蛋白具有环状AMP依赖的蛋白激酶的底物位点，其可能是分解代谢物失活的靶标。该转运蛋白缺乏一个强序列，富含脯氨酸（P），谷氨酸（E），天冬氨酸，丝氨酸（S）和苏氨酸（T），并且侧翼有碱性氨基酸（PEST序列），尽管它的半衰期很短。考虑了将不良PEST转换为可能的PEST序列的机制。像超家族的其他成员一样，半乳糖转运蛋白缺乏信号序列。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号