Morris R M, Fung J M, Rahm B G, Zhang S, Freedman D L, Zinder S H, Richardson R E
Civil and Environmental Engineering, Cornell University, Ithaca, NY 14853, USA.
Appl Environ Microbiol. 2007 Jan;73(1):320-6. doi: 10.1128/AEM.02129-06. Epub 2006 Nov 10.
Anaerobic reductive dehalogenation by Dehalococcoides spp. is an ideal system for studying functional diversity of closely related strains of bacteria. In Dehalococcoides spp., reductive dehalogenases (RDases) are key respiratory enzymes involved in the anaerobic detoxification of halogenated compounds at contaminated sites globally. Although housekeeping genes sequenced from Dehalococcoides spp. are >85% identical at the amino acid level, different strains are capable of dehalogenating diverse ranges of compounds, depending largely on the suite of RDase genes that each strain harbors and expresses. We identified RDase proteins that corresponded to known functions in four characterized cultures and predicted functions in an uncharacterized Dehalococcoides-containing mixed culture. Homologues within RDase subclusters containing PceA, TceA, and VcrA were among the most frequently identified proteins. Several additional proteins, including a formate dehydrogenase-like protein (Fdh), had high coverage in all strains and under all growth conditions.
脱卤球菌属进行的厌氧还原性脱卤作用是研究密切相关细菌菌株功能多样性的理想系统。在脱卤球菌属中，还原性脱卤酶（RDases）是关键的呼吸酶，参与全球受污染场地卤代化合物的厌氧解毒。尽管从脱卤球菌属测序的管家基因在氨基酸水平上有>85%的同一性，但不同菌株能够对不同范围的化合物进行脱卤，这在很大程度上取决于每个菌株所携带和表达的RDase基因组合。我们鉴定了与四种特征化培养物中的已知功能相对应以及在一种未特征化的含脱卤球菌属混合培养物中的预测功能相对应的RDase蛋白。含有PceA、TceA和VcrA的RDase亚簇中的同源物是最常鉴定出的蛋白之一。包括一种甲酸脱氢酶样蛋白（Fdh）在内的几种其他蛋白在所有菌株和所有生长条件下都有高覆盖率。
