title: A new cytoplasmic monoheme cytochrome c from Acidithiobacillus ferrooxidans involved in sulfur oxidation.
abstract: Acidithiobacillus ferrooxidans can obtain energy from the oxidation of various reduced inorganic sulfur compounds (RISCs, e.g., sulfur) and ferrous iron in bioleaching so has multiple branched respiratory pathways with a diverse range of electron transporters, especially cytochrome c proteins. A cytochrome c family gene, afe1130, which has never been reported before, was found by screening the whole genome of A. ferrooxidans. Here we report the differential gene transcription, bioinformatics analysis, and molecular modeling of the protein encoded by the afe1130 gene (AFE1130). The differential transcription of the target afe1130 gene versus the reference rrs gene in the A. ferrooxidans, respectively, on the culture conditions of sulfur and ferrous energy sources was performed through quantitative reverse transcription polymerase chain reaction (qRT-PCR) with a SYBR green-based assay according to the standard curves method. The qRT-PCR results showed that the afe1130 gene in sulfur culture condition was obviously more transcribed than that in ferrous culture condition. Bioinformatics analysis indicated that the AFE1130 was affiliated to the subclass ID of class I of cytochrome c and located in cytoplasm. Molecular modeling results exhibited that the AFE1130 protein consisted of 5 alpha-helices harboring one heme c group covalently bonded by Cys13 and Cys16 and ligated by His17 and Met62 and owned a big raised hydrophobic surface responsible for attaching to inner cytomembrane. So the AFE1130 in A. ferrooxidans plays a role in the RISCs oxidation in bioleaching in cytoplasm bound to inner membrane.
authors.affiliation: Key Lab of Biometallurgy of the Ministry of Education, School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, People's Republic of China, yuandong_liu@sina.cn.
authors.forename: Yuandong
authors.initials: Y
authors.lastname: Liu
authors.forename: Shuhui
authors.initials: S
authors.lastname: Guo
authors.forename: Runlan
authors.initials: R
authors.lastname: Yu
authors.forename: Kai
authors.initials: K
authors.lastname: Zou
authors.forename: Guanzhou
authors.initials: G
authors.lastname: Qiu
mesh_terms: D042763:Acidithiobacillus / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism*; D019295:Computational Biology; D045304:Cytochromes c / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D005296:Ferrous Compounds / Q000378:metabolism; D020869:Gene Expression Profiling; D008958:Models, Molecular; D010084:Oxidation-Reduction; D011487:Protein Conformation; D060888:Real-Time Polymerase Chain Reaction; D013455:Sulfur / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D005296:Ferrous Compounds; D013455:Sulfur; D045304:Cytochromes c