1887

Abstract

Race 1 isolates of are pathogenic on certain maize lines due to production of a host-selective cyclic tetrapeptide, HC-toxin. Flanking , which encodes the central enzyme in HC-toxin biosynthesis, a gene was identified and named . Like occurred only in isolates of the fungus that make HC-toxin and was present as two linked copies in most toxin-producing isolates. and were transcribed in the opposite orientation and their transcriptional start sites were 386 bp apart. The predicted product of was a 58 kDa hydrophobic protein with 10-13 membrane-spanning regions. The sequence was highly similar to several members of the major facilitator superfamily that confer resistance to tetracycline, methylenomycin, and other antibiotics. Although it was possible to mutate one copy or the other of by targeted gene disruption, numerous attempts to disrupt both copies in a single strain were unsuccessful, suggesting that is an essential gene in strains that synthesize HC-toxin. On the basis of its presence only in HC-toxin-producing strains, its proximity to and its predicted amino acid sequence, we propose that encodes an HC-toxin efflux pump which contributes to self-protection against HC-toxin and/or the secretion of HC-toxin into the extracellular milieu.

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1996-06-01
2021-10-22
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References

  1. Bronson C.R. The genetics of phytotoxin production by plant pathogenic fungi. Experientia 1991; 47:771–776
    [Google Scholar]
  2. Brosch G., Ransom R., Lechner T., Walton J.D., Loidl P. Inhibition of maize histone deacetylase by HC-toxin, the host-selective toxin of Cochliobolus carbonum. Plant Cell 1995; 7:1941–1950
    [Google Scholar]
  3. Caballero J.L., Martinez E., Malpartida F., Hopwood D.A. Organisation and functions of the actVA region of the actinorhodin biosynthetic gene cluster of Streptomyces coelicolor. Mol Gen Genet 1991; 230:401–412
    [Google Scholar]
  4. Callahan T.M., Upchurch R.G. The light induced gene, LE6, from Cercospora kikuchii encodes a putative transporter of the polyketide toxin cercosporin. In 95th General Meeting of the American Society for Microbiology 1995 Abstract 0-14, Washington, DC 370
    [Google Scholar]
  5. Chomczynski P., Sacchi N. Single step method of RNA extraction by acid guanidinium thiocyanate-phenol-chloroform extraction. Anal Biochem 1987; 162:156–159
    [Google Scholar]
  6. Eckert B., Beck C.F. Topology of the transposon TnlO-encoded tetracycline resistance protein within the inner membrane of Escherichia coli. J Biol Chem 1989; 264:11663–11670
    [Google Scholar]
  7. Edelmann S.E., Staben C. A statistical analysis of sequence features within genes from Neurospora crassa. Expt Mycol 1994; 18:70–81
    [Google Scholar]
  8. Ehrenhofer-Murray A.E., Wurgler F.E., Sengstag C. The Saccharomyces cerevisiae SGE1 gene product: a novel drug-resistance protein within the major facilitator superfamily. Mol Gen Genet 1994; 224:287–294
    [Google Scholar]
  9. Fling M.E., Kopf J., Tamarkin A., Gorman J.A., Smith H.A., Koltin Y. Analysis of a Candida albicans gene that encodes a novel mechanism for resistance to benomyl and methotrexate. Mol Gen Genet 1991; 227:318–329
    [Google Scholar]
  10. Frohman M.A., Dush M.K., Martin G.R. Rapid production of full length cDNAs from rare transcripts: amplification using a single gene-specific oligonucleotide primer. Proc Natl Acad Set USA 1988; 85:8998–9002
    [Google Scholar]
  11. Geever R.F., Huiet L., Baum J.A., Tyler B.M., Patel V.B., Rutledge B.J., Case M.E., Giles N.H. DNA sequence, organization and regulation of the qa gene cluster of Neurospora crassa. J Mol Biol 1989; 207:15–34
    [Google Scholar]
  12. Gish W., States D.J. Identification of protein coding regions by database similarity search. Nat Genet 1993; 3:266–272
    [Google Scholar]
  13. Guilfoile P.G., Hutchinson C.R. Sequence and transcriptional analysis of the Streptomyces glaucescens tcmAR tetracenomycin C resistance and repressor gene loci. J Bacteriol 1992a; 174:3651–3658
    [Google Scholar]
  14. Guilfoile P.G., Hutchinson C.R. The Streptomyces glaucescens TcmR protein represses transcription of the divergently oriented tcmR and tcmA genes by binding to an intergenic operator region. J Bacteriol 1992b; 174:3659–3666
    [Google Scholar]
  15. Henikoff S. Unidirectional digestion with exonuclease III creates targeted breakpoints for DNA sequencing. Gene 1984; 28:351–359
    [Google Scholar]
  16. Hynes M.J., Corrick C.M., King J.A. Isolation of genomic clones containing the amdS gene of Aspergillus nidulans and their use in the analysis of structural regulatory mutations. Mol Cell Biol 1983; 3:1430–1439
    [Google Scholar]
  17. Johnstone L.L., McCabe P.C., Greaves P., Gurr S.J., Cole G.E., Brow M.A.D., Unkles S.E., Clutterbuck A.J., Kinghorn J.R., Innis M.A. Isolation and characterization of the crnA- niiA-niaD gene cluster for nitrate assimilation in Aspergillus nidulans. Gene 1990; 90:181–192
    [Google Scholar]
  18. Jones D.T., Taylor W.R., Thornton J.M. A model recognition approach to the prediction of all-helical membrane protein structure and topology. Biochemistry 1994; 33:3038–3049
    [Google Scholar]
  19. Kyte J., Doolittle R.F. A simple method for displaying the hydropathic character of a protein. J Mol Biol 1982; 157:105–132
    [Google Scholar]
  20. Lomovskaya O.L., Lewis K. emr, an Escherichia coli locus for multidrug resistance. Proc Natl Acad Sci USA 1992; 89:8938–8942
    [Google Scholar]
  21. Marger M.D., Saier M.H. A major superfamily of transmembrane facilitators that catalyse uniport, symport and antiport. Trends Biochem Sci 1993; 18:13–20
    [Google Scholar]
  22. Meeley R.B., Johal G.S., Briggs S.P., Walton J.D. A biochemical phenotype for a disease resistance gene of maize. Plant Cell 1992; 4:71–77
    [Google Scholar]
  23. Neal R.J., Chater K.F. Nucleotide sequence analysis reveals similarities between proteins determining methylenomycin A resistance in Streptomyces and tetracycline resistance in eubacteria. Gene 1987; 58:229–241
    [Google Scholar]
  24. Panaccione D.G., Scott-Craig J.S., Pocard J.-A., Walton J.D. A cyclic peptide synthetase gene required for pathogenicity of the fungus Cochliobolus carbonum on maize. Proc Natl Acad Sci USA 1992; 89:6590–6594
    [Google Scholar]
  25. Rasmussen J.B., Scheffer R.P. Isolation and biological activities of four selective toxins from Helminthosporium carbonum. Plant Physiol 1988; 86:187–191
    [Google Scholar]
  26. Saghai-Maroof M.A., Soliman K.M., Jorgensen R.A., Allard R.W. Ribosomal DNA spacer-length polymorphisms in barley: Mendelian inheritance, chromosomal location, and population dynamics. Proc Natl Acad Sci USA 1984; 81:8014–8018
    [Google Scholar]
  27. Sambrook J., Fritsch E.F., Maniatis T. Molecular Cloning: a Laboratory Manual 1989 2nd edn Cold Spring Harbor, NY: Cold Spring Harbor Laboratory;
    [Google Scholar]
  28. Scheffer R.P., Ullstrup A.J. A host-specific metabolite from Helminthosporium carbonum. Phytopathology 1965; 55:1037–1038
    [Google Scholar]
  29. Scott-Craig J.S., Panaccione D.G., Cervone F., Walton J.D. Endopolygalacturonase is not required for pathogenicity of Cochliobolus carbonum on maize. Plant Cell 1990; 2:1191–1200
    [Google Scholar]
  30. Scott-Craig J.S., Panaccione D.G., Pocard J.-A., Walton J.D. The cyclic peptide synthetase catalyzing HC-toxin production in the filamentous fungus Cochliobolus carbonum is encoded by a 15'7-kilobase open reading frame. J Biol Chem 1992; 267:26044– 26049
    [Google Scholar]
  31. Shafer W., Straney D., Ciuffetti L., Van Etten H.D., Yoder O.C. One enzyme makes a fungal pathogen, but not a saprophyte, virulent on a new host plant. Science 1989; 246:247–249
    [Google Scholar]
  32. Sposato P., Ahn J.-H., Walton J.D. Characterization and disruption of a gene in the maize pathogen Cochliobolus carbonum encoding a cellulase lacking a cellulose binding domain and hinge region. Mol Plant-Microbe Interact 1995; 8:602–609
    [Google Scholar]
  33. Tzeng T.H., Lyngholm L.K., Ford C.F., Bronson C.R. A restriction fragment length polymorphism map and electrophoretic karytotype of the fungal maize pathogen Cochliobolus heterostrophus. Genetics 1992; 130:81–96
    [Google Scholar]
  34. Van Wert S.L., Yoder O.C. Structure of the Cochliobolus heterostrophus glyceraldehyde-3-phosphate dehydrogenase gene. Curr Genet 1992; 22:29–35
    [Google Scholar]
  35. Walton J.D., Holden F.R. Properties of two enzymes involved in biosynthesis of the fungal pathogenicity factor HC-toxin. Mol Plant-Microbe Interact 1988; 1:128–134
    [Google Scholar]
  36. Walton J.D., Earle E.D., Gibson B.W. Purification and structure of the host-specific toxin from Helminthosporium carbonum race 1. Biochem Biophys Res Commun 1982; 107:785–794
    [Google Scholar]
  37. Walton J.D., Ahn J.-H., Akimitsu K., Pitkin J.W., Ransom R. Leaf-spot disease of maize: chemistry, biochemistry and molecular biology of a host-selective cyclic peptide. In Advances in Molecular Genetics of Plant-Microbe Interactions 1994 Edited by Daniels M.J., Downie J.A., Osbourn A.E. Dordrecht: Kluwer; 4 pp 231–237
    [Google Scholar]
  38. Yoder O.C. Cochliobolus heterostrophus, cause of southern corn leaf blight. Adv Plant Path 1988; 6:93–112
    [Google Scholar]
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