Institute of Microbiology, University of Lausanne and University Hospital Center, Lausanne, Switzerland.
J Bacteriol. 2013 Aug;195(16):3543-51. doi: 10.1128/JB.00563-13. Epub 2013 May 31.
Catalase is an important virulence factor for survival in macrophages and other phagocytic cells. In Chlamydiaceae, no catalase had been described so far. With the sequencing and annotation of the full genomes of Chlamydia-related bacteria, the presence of different catalase-encoding genes has been documented. However, their distribution in the Chlamydiales order and the functionality of these catalases remain unknown. Phylogeny of chlamydial catalases was inferred using MrBayes, maximum likelihood, and maximum parsimony algorithms, allowing the description of three clade 3 and two clade 2 catalases. Only monofunctional catalases were found (no catalase-peroxidase or Mn-catalase). All presented a conserved catalytic domain and tertiary structure. Enzymatic activity of cloned chlamydial catalases was assessed by measuring hydrogen peroxide degradation. The catalases are enzymatically active with different efficiencies. The catalase of Parachlamydia acanthamoebae is the least efficient of all (its catalytic activity was 2 logs lower than that of Pseudomonas aeruginosa). Based on the phylogenetic analysis, we hypothesize that an ancestral class 2 catalase probably was present in the common ancestor of all current Chlamydiales but was retained only in Criblamydia sequanensis and Neochlamydia hartmannellae. The catalases of class 3, present in Estrella lausannensis and Parachlamydia acanthamoebae, probably were acquired by lateral gene transfer from Rhizobiales, whereas for Waddlia chondrophila they likely originated from Legionellales or Actinomycetales. The acquisition of catalases on several occasions in the Chlamydiales suggests the importance of this enzyme for the bacteria in their host environment.
过氧化氢酶是在巨噬细胞和其他吞噬细胞中生存的重要毒力因子。到目前为止，在衣原体科中还没有描述过过氧化氢酶。随着对衣原体相关细菌全基因组的测序和注释，已经记录了不同的过氧化氢酶编码基因的存在。然而，它们在衣原体目中的分布以及这些过氧化氢酶的功能仍然未知。使用 MrBayes、最大似然法和最大简约法推断了衣原体过氧化氢酶的系统发育，描述了三个 3 类和两个 2 类过氧化氢酶。只发现了单功能的过氧化氢酶（没有过氧化氢酶-过氧化物酶或 Mn-过氧化氢酶）。所有的都呈现出保守的催化结构域和三级结构。通过测量过氧化氢的降解来评估克隆的衣原体过氧化氢酶的酶活性。这些过氧化氢酶具有不同的酶活性效率。Parachlamydia acanthamoebae 的过氧化氢酶的效率最低（其催化活性比 Pseudomonas aeruginosa 低 2 个对数）。根据系统发育分析，我们假设一个祖先的 2 类过氧化氢酶可能存在于所有当前的衣原体目中，但仅在 Criblamydia sequanensis 和 Neochlamydia hartmannellae 中保留。3 类的过氧化氢酶，存在于 Estrella lausannensis 和 Parachlamydia acanthamoebae 中，可能是通过水平基因转移从 Rhizobiales 获得的，而对于 Waddlia chondrophila，它们可能来自 Legionellales 或 Actinomycetales。在衣原体目中多次获得过氧化氢酶表明，这种酶对细菌在宿主环境中的重要性。
