Molecular Genetic and Functional Analysis of the Genes Encoding Alkane 1‑Monoozygenase Synthesis in Members of the Genus <i>Rhodococcus</i>

Author:

Bulyarevich A. A.1,Gurinovich A. S.1,Filonov A. E.2,Titok M. A.1

Affiliation:

1. Belarusian State University

2. Skryabin Institute of Biochemistry and Physiology of Microorganisms

Abstract

Abstract—Organization and localization of the alkB genes and of alkane 1-monooxygenases they encode in members of the genus Rhodococcus was investigated. All members of a phylogenetic group were found to possess specific types of the alkB genes (alkB1-type in the operons containing rubredoxin-coding genes, rubredoxin reductase, and a regulatory protein and/or alkB2-type in the operons lacking the rubredoxin-reductase-coding gene, and supplementary, separately located determinants of the alkB3−alkB8 type). The alkB1-type genes were present in the chromosomes of bacteria of groups B1 (R. aetherivorans, R. ruber), С (R. opacus, R. jostii, R. wratislaviensis, R. koreensis), D (R. erythropolis, R. qingshengii), G (R. triatomae), and E (R. fascians). The alkB2-type genes occurred in strictly specified loci of the chromosomes of members of the phylogenetic groups А (R. hoagii/R. equi), В2 (R. coprophilus, R. pyridinivorans, R. rhodochrous), and D (R. erythropolis, R. qingshengii). The separately located alkB3−alkB5 were revealed in the chromosomes of members of the D group D (alkB5 was found only in R. qingshengii), the alkB6 genes occurred in members of the groups B1 and В2, and alkB7−alkB8 were present in members of group Е. The proteins coded by the genes alkB1 and alkB2 belonged to three phylogenetic groups. The first one comprised AlkB1-type proteins of members of groups В1 and С and the AlkB2-type proteins of members of groups D and A. The second one was represented by AlkB2-type proteins of bacteria of group В2. The third group comprised AlkB1-type proteins of members of groups G and D. Alkane 1-monooxygenases encoded by separately localized genes alkB3−alkB8 were represented by three phylogenetic lineages: AlkB3−AlkB5, AlkB6, and AlkB7 and AlkB8. In the genome of R. pyridinivorans 5Ар, the genes alkB2 and alkB6 characteristic of group В1 were revealed. This determinants were shown to be required for biosurfactant synthesis. Emulsifying activity of the mutant with impaired alkB2 gene at 28 and 42°С was 16 and 3 times lower, respectively, while the amount of trehalose-containing surfactants decreased 7 and 3 times, respectively. Independent on the cultivation temperature, the mutant with impaired alkB6 gene exhibited 1.2 times lower emulsifying activity and more than twofold lower decrease of the synthesis of trehalose-containing surfactants. These results indicated the key role of alkB2 in biosurfactant synthesis at different cultivation temperatures. The role of alkB6 increased at 42°С, probably due to its elevated transcriptional activity.

Publisher

The Russian Academy of Sciences

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3