Cui Hongli, Wang Yinchu, Qin Song
The Coastal Zone Bio-Resource Laboratory, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China.
Comp Funct Genomics. 2012;2012:164690. doi: 10.1155/2012/164690. Epub 2012 Feb 28.
Carotenoid cleavage dioxygenases (CCDs) are a group of enzymes that catalyze the oxidative cleavage steps from carotenoids to various carotenoid cleavage products. Some ccd genes have been identified and encoded enzymes functionally characterized in many higher plants, but little in cyanobacteria. We performed a comparative analysis of ccd sequences and explored their distribution, classification, phylogeny, evolution, and structure among 37 cyanobacteria. Totally 61 putative ccd sequences were identified, which are abundant in Acaryochloris marina MBIC 11017, filamentous N(2)-fixing cyanobacteria, and unicellular cyanobacterial Cyanothece. According to phylogenetic trees of 16S rDNA and CCD, nced and ccd8 genes occur later than the divergence of ccd7, apco, and ccd1. All CCD enzymes share conserved basic structure domains constituted by a single loop formed with seven β-strands and one helix. In this paper, a general framework of sequence-function-evolution connection for the ccd has been revealed, which may provide new insight for functional investigation.
类胡萝卜素裂解双加氧酶（CCDs）是一类催化类胡萝卜素氧化裂解为各种类胡萝卜素裂解产物的酶。在许多高等植物中已鉴定出一些ccd基因并对其编码的酶进行了功能表征，但在蓝细菌中了解甚少。我们对37种蓝细菌中的ccd序列进行了比较分析，并探讨了它们的分布、分类、系统发育、进化和结构。共鉴定出61个假定的ccd序列，这些序列在滨海蓝藻Acaryochloris marina MBIC 11017、丝状固氮蓝细菌和单细胞蓝细菌蓝藻属中丰富。根据16S rDNA和CCD的系统发育树，nced和ccd8基因的出现晚于ccd7、apco和ccd1的分化。所有CCD酶都共享由七个β链和一个螺旋形成的单个环构成的保守基本结构域。本文揭示了ccd序列-功能-进化联系的一般框架，这可能为功能研究提供新的见解。
