RRC ID 35582
著者 Nagayasu E, Ishikawa SA, Taketani S, Chakraborty G, Yoshida A, Inagaki Y, Maruyama H.
タイトル Identification of a bacteria-like ferrochelatase in Strongyloides venezuelensis, an animal parasitic nematode.
ジャーナル PLoS One
Abstract Heme is an essential molecule for vast majority of organisms serving as a prosthetic group for various hemoproteins. Although most organisms synthesize heme from 5-aminolevulinic acid through a conserved heme biosynthetic pathway composed of seven consecutive enzymatic reactions, nematodes are known to be natural heme auxotrophs. The completely sequenced Caenorhabditis elegans genome, for example, lacks all seven genes for heme biosynthesis. However, genome/transcriptome sequencing of Strongyloides venezuelensis, an important model nematode species for studying human strongyloidiasis, indicated the presence of a gene for ferrochelatase (FeCH), which catalyzes the terminal step of heme biosynthesis, whereas the other six heme biosynthesis genes are apparently missing. Phylogenetic analyses indicated that nematode FeCH genes, including that of S. venezuelensis (SvFeCH) have a fundamentally different evolutionally origin from the FeCH genes of non-nematode metazoa. Although all non-nematode metazoan FeCH genes appear to be inherited vertically from an ancestral opisthokont, nematode FeCH may have been acquired from an alpha-proteobacterium, horizontally. The identified SvFeCH sequence was found to function as FeCH as expected based on both in vitro chelatase assays using recombinant SvFeCH and in vivo complementation experiments using an FeCH-deficient strain of Escherichia coli. Messenger RNA expression levels during the S. venezuelensis lifecycle were examined by real-time RT-PCR. SvFeCH mRNA was expressed at all the stages examined with a marked reduction at the infective third-stage larvae. Our study demonstrates the presence of a bacteria-like FeCH gene in the S. venezuelensis genome. It appeared that S. venezuelensis and some other animal parasitic nematodes reacquired the once-lost FeCH gene. Although the underlying evolutionary pressures that necessitated this reacquisition remain to be investigated, it is interesting that the presence of FeCH genes in the absence of other heme biosynthesis genes has been reported only for animal pathogens, and this finding may be related to nutritional availability in animal hosts.
巻・号 8(3)
ページ e58458
公開日 2013-1-1
DOI 10.1371/journal.pone.0058458
PII PONE-D-12-23085
PMID 23516484
PMC PMC3596385
MeSH Amino Acid Sequence Animals Base Sequence Enzyme Activation Ferrochelatase / chemistry Ferrochelatase / genetics Ferrochelatase / metabolism* Gene Expression Regulation Genetic Complementation Test Molecular Sequence Data Phylogeny Recombinant Proteins Sequence Alignment Strongyloides / classification Strongyloides / enzymology* Strongyloides / genetics
IF 2.74
引用数 5
WOS 分野 BIOCHEMISTRY & MOLECULAR BIOLOGY
リソース情報
原核生物(大腸菌) IH71(VS200)