Structural and Genomic Insights Into Pyrazinamide Resistance in Mycobacterium tuberculosis Underlie Differences Between Ancient and Modern Lineages.
Structural and Genomic Insights Into Pyrazinamide Resistance in Mycobacterium tuberculosis Underlie Differences Between Ancient and Modern Lineages.
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DOI：
10.3389/fmolb.2021.619403
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发表时间：
2021
影响因子：
5
通讯作者：
Furnham N
中科院分区：
文献类型：
--
作者：
Tunstall T;Phelan J;Eccleston C;Clark TG;Furnham N
对用于治疗结核病（TB）的药物的耐药性仍然是一个公共卫生负担，几乎所有抗TB药物都描述了潜在结核分枝杆菌细菌中的错义点突变。后基因组学时代沿着计算和结构生物学的进步，为理解M.与耐药性有关的结核病突变。吡嗪酰胺（PZA）是目前用于结核病治疗方案的关键一线抗生素。pncA基因（PZA的靶基因）所表现出的突变混杂性需要计算方法来研究PZA抗性发展的遗传和结构基础。我们分析了424个错义点突变与PZA耐药源自p35 KM。结核病临床分离株来源于全球，其中包括四个主要的M。肺结核谱系（谱系1-4）。注释突变以反映其与PZA抗性的关联。基因组措施（次要等位基因频率和比值比），结构特征（表面积，残基深度和疏水性）和生物物理效应（稳定性和配体亲和力的变化）的点突变对pncA蛋白的稳定性和配体亲和力进行了评估。pncA内的错义点突变分布在整个基因中，大多数（>80%）突变对原聚体稳定性和配体亲和力具有不稳定作用。参与PZA结合的活性位点残基与多个点突变相关，由于这些功能重要位点的选择压力，突出了突变多样性。基因组测量和突变的生物物理效应之间存在弱关联。然而，与PZA抗性相关的突变显示结构特征（表面积和残基深度）之间的统计学显著差异，但突变位点的疏水性评分没有差异。最有趣的是M。与现代谱系相比，结核病谱系1（古代谱系）对于与PZA抗性相关的突变表现出不同的蛋白质稳定性谱。
Resistance to drugs used to treat tuberculosis disease (TB) continues to remain a public health burden, with missense point mutations in the underlying Mycobacterium tuberculosis bacteria described for nearly all anti-TB drugs. The post-genomics era along with advances in computational and structural biology provide opportunities to understand the interrelationships between the genetic basis and the structural consequences of M. tuberculosis mutations linked to drug resistance. Pyrazinamide (PZA) is a crucial first line antibiotic currently used in TB treatment regimens. The mutational promiscuity exhibited by the pncA gene (target for PZA) necessitates computational approaches to investigate the genetic and structural basis for PZA resistance development. We analysed 424 missense point mutations linked to PZA resistance derived from ∼35K M. tuberculosis clinical isolates sourced globally, which comprised the four main M. tuberculosis lineages (Lineage 1–4). Mutations were annotated to reflect their association with PZA resistance. Genomic measures (minor allele frequency and odds ratio), structural features (surface area, residue depth and hydrophobicity) and biophysical effects (change in stability and ligand affinity) of point mutations on pncA protein stability and ligand affinity were assessed. Missense point mutations within pncA were distributed throughout the gene, with the majority (>80%) of mutations with a destabilising effect on protomer stability and on ligand affinity. Active site residues involved in PZA binding were associated with multiple point mutations highlighting mutational diversity due to selection pressures at these functionally important sites. There were weak associations between genomic measures and biophysical effect of mutations. However, mutations associated with PZA resistance showed statistically significant differences between structural features (surface area and residue depth), but not hydrophobicity score for mutational sites. Most interestingly M. tuberculosis lineage 1 (ancient lineage) exhibited a distinct protein stability profile for mutations associated with PZA resistance, compared to modern lineages.