Baudry B, Kaczorek M, Sansonetti P J
Service des Entérobactéries, Unité INSERM 199, Institut Pasteur, Paris, France.
Microb Pathog. 1988 May;4(5):345-57. doi: 10.1016/0882-4010(88)90062-9.
The nucleotide sequence of a 4.8 kilobase (kb) HindIII fragment from pWR100, the virulence plasmid of Shigella flexneri 5, was determined and analysed. This fragment encodes polypeptides b (62 kilodalton, kD) and c (43 kD) which have already been described as two of the four immunogenic polypeptides of Shigellae. The nucleotide sequence revealed that in addition to the ipaB and ipaC genes encoding polypeptides b and c, a third complete open reading frame was found within the fragment. The gene, named ippI, encoded a 17 kD polypeptide. The deduced amino acids sequence of polypeptides b and c showed no signal peptide but presence of highly hydrophobic domains compatible with a transmembraneous location. The surprising A and T richness of the three genes as compared with the Escherichia coli and Shigella genomes, resulted in a biased codon usage, and raises the question of the origin of the sequences.
测定并分析了来自福氏志贺菌5型毒力质粒pWR100的一个4.8千碱基（kb）HindIII片段的核苷酸序列。该片段编码多肽b（62千道尔顿，kD）和多肽c（43 kD），这两种多肽已被描述为志贺菌四种免疫原性多肽中的两种。核苷酸序列显示，除了编码多肽b和c的ipaB和ipaC基因外，在该片段内还发现了第三个完整的开放阅读框。该基因命名为ippI，编码一种17 kD的多肽。多肽b和c的推导氨基酸序列没有信号肽，但存在与跨膜定位相符的高度疏水结构域。与大肠杆菌和志贺菌基因组相比，这三个基因惊人的A和T丰富度导致了密码子使用的偏向性，并引发了序列起源的问题。
