Codon usage and base composition in Rickettsia prowazekii
Codon usage and base composition in Rickettsia prowazekii
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DOI：
10.1007/bf02352282
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发表时间：
1996-05-01
影响因子：
3.9
通讯作者：
Sharp, PM
中科院分区：
文献类型：
--
作者：
Andersson, SGE;Sharp, PM
已经研究了普氏立克次体（α变形菌门的成员）富含 A + T 的基因组序列中的密码子使用和碱基组成。尽管数据集包括预计以非常不同的水平表达的基因，但基因之间的同义密码子使用模式大致相似，这表明翻译选择在该物种中无效。然而，多变量统计分析根据前两个密码子位置的 G + C 含量来区分基因。为了研究这种变异，我们将 21 种 R. prowazekii 蛋白的氨基酸组成模式与来自大肠杆菌的一组同源蛋白的氨基酸组成模式进行了比较。分析表明，个体基因在不同程度上受到偏差突变率的影响：编码在其他物种中高度保守的蛋白质的基因受影响最小。总体而言，蛋白质编码区和基因间间隔区的 G + C 含量值分别为 32.5% 和 21.4%。从这些值推断，P. prowazekii 有大约 800 个基因，并且 60-70% 的基因组可能是编码的。
Codon usage and base composition in sequences from the A + T-rich genome of Rickettsia prowazekii, a member of the alpha Proteobacteria, have been investigated. Synonymous codon usage patterns are roughly similar among genes, even though the data set includes genes expected to be expressed at very different levels, indicating that translational selection has been ineffective in this species. However, multivariate statistical analysis differentiates genes according to their G + C contents at the first two codon positions. To study this variation, we have compared the amino acid composition patterns of 21 R. prowazekii proteins with that of a homologous set of proteins from Escherichia coli. The analysis shows that individual genes have been affected by biased mutation rates to very different extents: genes encoding proteins highly conserved among other species being the least affected. Overall, protein coding and intergenic spacer regions have G + C content values of 32.5% and 21.4%, respectively. Extrapolation from these values suggests that P. prowazekii has around 800 genes and that 60-70% of the genome may be coding.