一个小的多基因家族编码鱼腥藻PCC7120藻胆体的杆状核心连接多肽。

A small multigene family encodes the rod-core linker polypeptides of Anabaena sp. PCC7120 phycobilisomes.

作者信息

Bryant D A, Stirewalt V L, Glauser M, Frank G, Sidler W, Zuber H

机构信息

Department of Molecular and Cell Biology, Pennsylvania State University, University Park 16802.

出版信息

Gene. 1991 Oct 30;107(1):91-9. doi: 10.1016/0378-1119(91)90301-q.

DOI:10.1016/0378-1119(91)90301-q

PMID:1743523

Abstract

The cpc operon of Anabaena sp. PCC7120 is shown to encode ten genes: 5'-cpcB-cpcA-cpcC-cpcD-cpcE-cpcF- cpcG1-cpcG2-cpcG3-cpcG4-3'. The 3' portion of this operon includes four tandemly repeated genes encoding phycocyanin (PC)-associated, rod-core linker polypeptides of the phycobilisomes (PBS). The products of these four genes are most similar at their N termini, and overall are 50-61% identical and 68-76% similar to one another. The four CpcG proteins of Anabaena sp. PCC7120 are 41-47% identical and 62-65% similar to the single CpcG rod-core linker protein in Synechococcus sp. PCC7002. The N-terminal domains of the polypeptides are also more distantly related to the conserved domains of other types of rod-linker polypeptides associated with PC, phycoerythrin, and allophycocyanin (AP). Three of these rod-core linker proteins (CpcG1, CpcG2, and CpcG4) were demonstrated to occur in isolated PBS by N-terminal amino acid sequence analyses. These results indicate that previously proposed models for the PBS of Anabaena sp. are incorrect. It is suggested that the PBS of Anabaena sp. have eight peripheral rods, each of which interacts with the AP of the core via a specific rod-core linker (CpcG) polypeptide.

摘要

已证明鱼腥藻PCC7120的cpc操纵子编码10个基因：5'-cpcB-cpcA-cpcC-cpcD-cpcE-cpcF-cpcG1-cpcG2-cpcG3-cpcG4-3'。该操纵子的3'部分包含四个串联重复基因，这些基因编码与藻胆体（PBS）的藻蓝蛋白（PC）相关的杆状核心连接多肽。这四个基因的产物在其N端最为相似，总体上彼此的同一性为50-61%，相似性为68-76%。鱼腥藻PCC7120的四种CpcG蛋白与聚球藻PCC7002中的单个CpcG杆状核心连接蛋白的同一性为41-47%，相似性为62-65%。这些多肽的N端结构域与其他类型的与PC、藻红蛋白和别藻蓝蛋白（AP）相关的杆状连接多肽的保守结构域的关系也更远。通过N端氨基酸序列分析证明，其中三种杆状核心连接蛋白（CpcG1、CpcG2和CpcG4）存在于分离的PBS中。这些结果表明，先前提出的鱼腥藻PBS模型是不正确的。有人提出，鱼腥藻的PBS有八个外周杆，每个外周杆通过特定的杆状核心连接（CpcG）多肽与核心的AP相互作用。