Chelikani P, Fita I, Loewen P C
Department of Microbiology, University of Manitoba, Winnipeg MB, R3T 2N2, Canada.
Cell Mol Life Sci. 2004 Jan;61(2):192-208. doi: 10.1007/s00018-003-3206-5.
More than 300 catalase sequences are now available, divided among monofunctional catalases (> 225), bifunctional catalase-peroxidases (> 50) and manganese-containing catalases (> 25). When combined with the recent appearance of crystal structures from at least two representatives from each of these groups (nine from the monofunctional catalases), valuable insights into the catalatic reaction mechanism in its various forms and into catalase evolution have been gained. The structures have revealed an unusually large number of modifications unique to catalases, a result of interacting with reactive oxygen species. Biochemical and physiological characterization of catalases from many different organisms has revealed a surprisingly wide range of catalatic efficiencies, despite similar sequences. Catalase gene expression in micro-organisms generally is controlled either by sensors of reactive oxygen species or by growth phase regulons, although the detailed mechanisms vary considerably.
目前已有300多个过氧化氢酶序列，分布在单功能过氧化氢酶（>225个）、双功能过氧化氢酶-过氧化物酶（>50个）和含锰过氧化氢酶（>25个）之中。当这些序列与最近从每组中至少两个代表（单功能过氧化氢酶中有九个）获得的晶体结构相结合时，人们对各种形式的催化反应机制以及过氧化氢酶的进化有了宝贵的见解。这些结构揭示了过氧化氢酶特有的大量修饰，这是与活性氧相互作用的结果。对来自许多不同生物体的过氧化氢酶进行生化和生理特性分析发现，尽管序列相似，但催化效率的范围却惊人地广泛。微生物中过氧化氢酶基因的表达通常由活性氧传感器或生长阶段调节子控制，不过具体机制差异很大。
