Abstract
Telomere-linked RecQ helicase (TLH) genes have been identified in several fungi, where they occur as small gene families with each member copy residing within ~10 kb of a telomere. Here we describe the characterization of all 11 TLH gene copies in the reference strain of the fungus Magnaporthe oryzae. A consensus gene prediction revealed that the previously reported TLH1 gene is actually a mutated copy, and the full-length gene is almost two times longer. Only four full-length TLH genes were present in the strain that was analyzed, with the remaining copies containing premature stops caused by point mutations, indels, transposon insertions, and a telomere truncation. Interestingly, all of the TLH gene copies possessed numerous mutations indicative of the action of the repeat-induced point mutation process. However, there was evidence of purifying selection indicating maintenance of gene function. Alignment of full-length proteins from M. oryzae, Schizosaccharomyces pombe and M. anisopliae revealed the presence of a novel, highly conserved protein motif which suggests that the telomere-linked helicases have different functions and/or substrates to the RecQ helicases encoded by “internal” genes.
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Acknowledgments
We thank Angela Schoegendorfer for assistance with the statistical analysis. This work was supported by National Science Foundation (NSF) grants MCB 0135462 and MCB 0653930, and an NSF Graduate Research Fellowship to C.J.R. This is Kentucky Agricultural Experiment Station (K.A.E.S.) publication no. 09-12-1 and is published with the permission of the director.
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Communicated by D. Ebbole.
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Rehmeyer, C.J., Li, W., Kusaba, M. et al. The telomere-linked helicase (TLH) gene family in Magnaporthe oryzae: revised gene structure reveals a novel TLH-specific protein motif. Curr Genet 55, 253–262 (2009). https://doi.org/10.1007/s00294-009-0240-3
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DOI: https://doi.org/10.1007/s00294-009-0240-3