Purine and pyrimidine nucleotide metabolism in Mollicutes
Purine and pyrimidine nucleotide metabolism in Mollicutes
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DOI：
10.1590/s1415-47572007000200005
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发表时间：
2007-01-01
影响因子：
2.1
通讯作者：
Schuck, Desirée Cigaran
中科院分区：
文献类型：
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作者：
Bizarro, Cristiano Valim;Schuck, Desirée Cigaran
几个软体动物基因组项目正在进行中，为在全基因组范围内研究基因和代谢途径提供了独特的机会。在这里，我们分析了支原体中嘌呤和嘧啶代谢的保守性和多样性。对基因组分析和酶数据之间差异的评估揭示了这些生物体的有趣方面。我们发现了一些重要的例子，其中报告的酶活性没有相应基因的注释。一个有趣的例子涉及磷酸五肽变位酶。在 Mollicutes 中，我们鉴定了与最近在古细菌中鉴定为新的磷酸戊糖变位酶的序列直系同源的 CDS，其在结构上与磷酸甘露聚糖坚果酶相关。有人认为，这些序列可以取代缺乏典型磷酸五角坚果酶基因（deoB）的软体动物中磷酸五角坚果酶的功能。此外，在不具有任何与 ushA 相关的 CDS 的软体动物中也报道了 5'-核苷酸酶的活性。假设的蛋白质表现出与大肠杆菌中新鉴定的 5' 核酸酶类似的结构域，被认为是与软体动物中的这种酶活性相关的可能的 CDS。根据我们的分析，软体动物的还原基因组进化似乎并没有产生所有软体动物物种共有的最小基因组或最小代谢功能组。
Several mollicute genome projects are underway, offering unique opportunities to study genes and metabolic pathways on a genome-wide scale. Here, we have analyzed the conservation and diversity of purine and pyrimidine metabolism in mycoplasmas. An evaluation of discrepancies between genomic analysis and enzymatic data revealed interesting aspects about these organisms. We found important examples in which enzyme activity was reported without the annotation of a corresponding gene. An interesting example concerns phosphopentomutase. In Mollicutes, we have identified CDSs orthologous to sequences recently identified as new phosphopentomutases in archaeobacteria that are structurally related to phosphomannornutases. It is suggested that these sequences could replace the function of phosphopentornutases in mollicutes lacking the canonical phosphopentornutase gene (deoB). Also, the activity of 5'-nucleotidase was reported in mollicutes that do not possess any CDS related to ushA. Hypothetical proteins exhibiting domains similar to newly characterized 5' nucleoticlases in Escherichia coli are proposed as possible CDSs related to this enzymatic activity in Mollicutes. Based on our analysis, the reductive genome evolution of Mollicutes does not appear to result in a minimum set of genes nor a minimum set of metabolic functions shared by all mollicute species.