Guiseppi A, Aymeric J L, Cami B, Barras F, Creuzet N
Laboratorie de Chimie Bactérinne, CNRS, Marseille, France.
Gene. 1991 Sep 30;106(1):109-14. doi: 10.1016/0378-1119(91)90573-t.
The Erwinia chrysanthemi (strain 3937) celY gene encoding the minor endoglucanase (EGY) was sequenced. The analysis of the upstream region allowed us to identify an in vivo active promoter recognized by the NtrA (sigma 54) holoenzyme. No similarity was found between the predicted amino acid (aa) sequences of EGY and either the Er. chrysanthemi major endoglucanase, EGZ, or the Er. carotovora CelS endoglucanase. In contrast, a very high level of identity, both at the nucleotide and the predicted aa levels, was found between celY and an EG-encoding gene from Cellulomonas uda, a Gram + bacterium taxonomically distant from Er. chrysanthemi. By comparing the molar G + C% of the cellulase-encoding genes and that of Er. chrysanthemi and C. uda chromosomal DNAs, we speculate that celY was transferred from Er. chrysanthemi to C. uda.
对编码小内切葡聚糖酶（EGY）的菊欧文氏菌（菌株3937）celY基因进行了测序。对上游区域的分析使我们能够鉴定出一个由NtrA（σ54）全酶识别的体内活性启动子。在EGY的预测氨基酸（aa）序列与菊欧文氏菌主要内切葡聚糖酶EGZ或胡萝卜软腐欧文氏菌CelS内切葡聚糖酶之间未发现相似性。相反，在核苷酸水平和预测的氨基酸水平上，celY与来自嗜纤维单胞菌的一个EG编码基因之间都有非常高的同一性，嗜纤维单胞菌是一种与菊欧文氏菌在分类学上距离较远的革兰氏阳性细菌。通过比较编码纤维素酶的基因以及菊欧文氏菌和嗜纤维单胞菌染色体DNA的摩尔G + C%，我们推测celY是从菊欧文氏菌转移到嗜纤维单胞菌的。
