CONTRASTING PATTERNS OF EVOLUTIONARY DIVERGENCE WITHIN THE ACINETOBACTER-CALCOACETICUS PCA OPERON
CONTRASTING PATTERNS OF EVOLUTIONARY DIVERGENCE WITHIN THE ACINETOBACTER-CALCOACETICUS PCA OPERON
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DOI：
10.1016/0378-1119(94)90829-x
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发表时间：
1994-08-19
期刊：
影响因子：
3.5
通讯作者：
ORNSTON, LN
中科院分区：
文献类型：
--
作者：
KOWALCHUK, GA;HARTNETT, GB;ORNSTON, LN
将原儿茶酸催化转化为琥珀酸和乙酰辅酶A所需的六种酶由革兰氏（-）细菌乙酸钙不动杆菌中的pen基因编码。聚簇的A.醋酸钙菌CAT基因编码一组与儿茶酚代谢异化相关的类似酶。本文报道的pcaIJFB和pcaK的核苷酸（nt）序列，完整的证据表明，所有的pen结构基因在单个操纵子内以pcaIJFBDKCHG的顺序紧密分组。pcaIJF区与A.乙酸钙杆菌catIJF区的G+C含量和密码子使用模式与A.醋酸钙相比之下，pcaD，pcaC，pcaH和pcaG已经从它们在猫区域的进化对应物中分化了很大的差异;所有这些分化的基因都表现出A的典型的G+C含量和密码子使用模式。醋酸钙已知pcaIJF和catIJF区域交换DNA序列信息，并且这种性质可能有助于它们的nt序列保守性。pcaK基因在已知的猫基因中没有对应的基因。推测的氨基酸序列表明PcaK可能是一种与转运相关的跨膜蛋白。
The six enzymes required for catabolism of protocatechuate to succinate and acetylCoA are encoded by the pen genes in the Gram(-) bacterium, Acinetobacter calcoaceticus. The clustered A. calcoaceticus cat genes encode an analogous set of enzymes associated with the metabolic dissimilation of catechol. The nucleotide (nt) sequences of pcaIJFB and pcaK, reported here, complete evidence showing that all of the pen structural genes are tightly grouped in the order pcaIJFBDKCHG within a single operon. The pcaIJF region is nearly identical in nt sequence to the A. calcoaceticus catIJF region which exhibits a G+C content and a codon usage pattern exceptional for A. calcoaceticus. In contrast, pcaD, pcaC, pcaH and pcaG have diverged substantially from their evolutionary counterparts in the cat region; all of these divergent genes exhibit G+C contents and codon usage patterns that are typical for A. calcoaceticus. The pcaIJF and catIJF regions are known to exchange DNA sequence information, and this property may have contributed to their nt sequence conservation. The pcaK gene has no counterpart among known cat genes. The deduced amino-acid sequence of PcaK indicates that it may be a transmembrane protein associated with transport.