Leroux M R, Candido E P
Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, Canada.
DNA Cell Biol. 1995 Nov;14(11):951-60. doi: 10.1089/dna.1995.14.951.
In this report we present the sequences of four new cct chaperonin genes from the nematode Caenorhabditis elegans. The four genes, cct-2, cct-4, cct-5, and cct-6 are orthologs of the mouse chaperonin genes Cctb, Cctd, Ccte, and Cctz, sharing 66%, 63%, 68%, and 67% deduced amino acid sequence identity, respectively. The C. elegans multigene family includes these four genes as well as cct-1 (tcp-1), and displays 23-35% pairwise predicted amino acid sequence identity between members, and 31-35% identity to the closely related archaebacterial chaperonin TF55. The five C. elegans cct genes are expressed in all life stages (egg, four larval stages, and adult). Members of the multigene family occur as a loosely associated group of three genes on chromosome II, and two widely separated genes on chromosome III. The predicted secondary structures of all five C. elegans CCT deduced protein sequences are nearly identical. Moreover, all chaperonins examined had comparable predicted secondary structures. Algorithmic predictions of the secondary structures of GroEL, Hsp60, and Rubisco subunit-binding protein (RuBP) are almost identical, and are very similar to the known GroEL secondary structure. The CCT/TF55 family predicted secondary structures are essentially identical to each other and are also related to GroEL, Hsp60, and RuBP. The most notable difference between the CCT/TF55 and the GroEL/Hsp60/RuBP families is in the presumed polypeptide binding domain.
在本报告中，我们展示了来自线虫秀丽隐杆线虫的四个新的CCT伴侣蛋白基因的序列。这四个基因，即cct-2、cct-4、cct-5和cct-6，是小鼠伴侣蛋白基因Cctb、Cctd、Ccte和Cctz的直系同源基因，推导的氨基酸序列同一性分别为66%、63%、68%和67%。秀丽隐杆线虫的多基因家族包括这四个基因以及cct-1（tcp-1），其成员之间的成对预测氨基酸序列同一性为23%-35%，与密切相关的古细菌伴侣蛋白TF55的同一性为31%-35%。秀丽隐杆线虫的五个cct基因在所有生命阶段（卵、四个幼虫阶段和成虫）均有表达。多基因家族的成员在染色体II上以三个基因的松散关联组形式出现，在染色体III上有两个相距甚远的基因。秀丽隐杆线虫所有五个CCT推导蛋白序列的预测二级结构几乎相同。此外，所有检测的伴侣蛋白都具有可比的预测二级结构。GroEL、Hsp60和核酮糖-1,5-二磷酸羧化酶亚基结合蛋白（RuBP）二级结构的算法预测几乎相同，并且与已知的GroEL二级结构非常相似。CCT/TF55家族预测的二级结构彼此基本相同，并且也与GroEL、Hsp60和RuBP相关。CCT/TF55与GroEL/Hsp60/RuBP家族之间最显著的差异在于推测的多肽结合结构域。
