title: Primary structure of dihydrofolate reductase and mitochondrial ribosomal protein L36 genes from the basidiomycete Coprinus cinereus.
abstract: We amplified and sequenced the dihydrofolate reductase (DHFR) gene of the basidiomycete Coprinus cinereus. Downstream of the DHFR coding region, a mitochondrial (mt) ribosomal protein L36 (RPL36) gene was discovered in the opposite orientation to DHFR gene. Putative polyadenylation signals of the two genes overlapped, both containing the 8-bp palindrome 5'-aatatatt-3'. The finding that C. cinereus DHFR gene is closely clustered with a mt protein gene strongly suggests that C. cinereus DHFR is closely related to mt function and evolution. The amino acid sequence of C. cinereus DHFR is most homologous to eukaryotic proteins such as Cryptococcus neoformans and Pneumocystis carinii DHFRs. However, the sequence of C. cinereus mt RPL36 closely resembles RPL36 of bacteria and cyanobacteria such as Synechocystis sp. and Escherichia coli. This result strongly supports the serial endosymbiotic theory of the development of ancestral eukaryotes, and suggests that C. cinereus mt RPL36 gene originated from the ancestral eubacterial genome.
authors.affiliation: Faculty of Agriculture, Tottori University, 4-101, Koyama-cho Minami, Tottori 680-8553, Japan.
authors.forename: Tadanori
authors.initials: T
authors.lastname: Aimi
authors.forename: Shoji
authors.initials: S
authors.lastname: Fukuhara
authors.forename: Maki
authors.initials: M
authors.lastname: Ishiguro
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Kitamoto
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Morinaga
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003302:Coprinus / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism; D024101:Mitochondrial Proteins / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D010802:Phylogeny; D012269:Ribosomal Proteins / Q000235:genetics* / Q000378:metabolism; D017422:Sequence Analysis, DNA; D013762:Tetrahydrofolate Dehydrogenase / Q000235:genetics* / Q000378:metabolism
chemical_list: D005656:Fungal Proteins; D024101:Mitochondrial Proteins; D012269:Ribosomal Proteins; D013762:Tetrahydrofolate Dehydrogenase