A double-stranded RNA element from a hypovirulent strain of Rhizoctonia solani occurs in DNA form and is genetically related to the pentafunctional AROM protein of the shikimate pathway

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 95; no. 11; pp. 6425 - 6429
• Main Authors: Lakshman, D.K. (University of Maine, Orono, ME.), Jian, J, Tavantzis, S.M
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences of the United States of America 26.05.1998; National Acad Sciences; National Academy of Sciences; The National Academy of Sciences
• Subjects: ACIDE ORGANIQUE; ACIDOS ORGANICOS; ADN; Amino Acid Sequence; AMINO ACID SEQUENCES; Amino acids; ARN; Base Sequence; Biological Sciences; CHEMICAL COMPOSITION; CITOPLASMA; CODE GENETIQUE; CODIGO GENETICO; COMPARISONS; COMPLEMENTARY DNA; COMPOSICION QUIMICA; COMPOSITION CHIMIQUE; CYTOPLASM; CYTOPLASME; DNA; DNA HYBRIDIZATION; DNA, Complementary - analysis; DNA, Complementary - genetics; DNA, Fungal - genetics; Double stranded RNA; ENZIMAS; ENZYME; ENZYMES; Fungal Proteins - genetics; Fungi; GENBANK/U51331; GENETIC CODE; Genetics; HIBRIDACION DE ADN; HYBRIDATION D'ADN; METABOLISM; METABOLISME; METABOLISMO; Microbiology; MITOCHONDRIA; MITOCHONDRIE; MITOCONDRIA; MOLECULAR SEQUENCE DATA; NUCLEIC PROBES; NUCLEOTIDE SEQUENCE; Open reading frames; ORGANIC ACIDS; Phylogeny; Polymerase chain reaction; PROTEINAS; PROTEINE; PROTEINS; Rhizoctonia - genetics; Rhizoctonia - pathogenicity; RHIZOCTONIA SOLANI; Ribonucleic acid; RNA; RNA POLYMERASE; RNA, Fungal - genetics; SECUENCIA NUCLEOTIDICA; Sequence Analysis; SEQUENCE NUCLEOTIDIQUE; Sequencing; SHIKIMIC ACID; SONDAS NUCLEICAS; SONDE NUCLEIQUE; TRANSFERASAS; TRANSFERASE; TRANSFERASES; Virulence
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.95.11.6425

M2 is a double-stranded RNA (dsRNA) element occurring in the hypovirulent isolate Rhs 1A1 of the plant pathogenic basidiomycete Rhizoctomia solani. Rhs 1A1 originated as a sector of the virulent field isolate Rhs 1AP, which contains no detectable amount of the M2 dsRNA. The complete sequence (3,570 bp) of the M2 dsRNA has been determined. A 6.9-kbp segment of total DNA from either Rhs 1A1 or Rhs 1AP hybridizes with an M2-specific cDNA probe. The sequences of M2 dsRNA and of PCR products generated from Rhs 1A1 total DNA were found to be identical. Thus this report describes a fungal host containing full-length DNA copies of a dsRNA element. A major portion of the M2 dsRNA is located in the cytoplasm, whereas a smaller amount is found in mitochondria. Based on either the universal or the mitochondrial genetic code of filamentous fungi, one strand of M2 encodes a putative protein of 754 amino acids. The resulting polypeptide has all four motifs of a dsRNA viral RNA-dependent RNA polymerase (RDRP) and is phylogenetically related to the RDRP of a mitochondrial dsRNA associated with hypovirulence in strain NB631 of Cryphonectria parasitica, incitant of chestnut blight. This polypeptide also has significant sequence similarity with two domains of a pentafunctional polypeptide, which catalyzes the five central steps of the shikimate pathway in yeast and filamentous fungi