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Title: Genetic and biochemical characterization of the GH72 family of cell wall transglycosylases in Neurospora crassa

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Journal Article: Publisher's Accepted Manuscript
Journal Name:
Fungal Genetics and Biology
Additional Journal Information:
Journal Volume: 101; Journal Issue: C; Related Information: CHORUS Timestamp: 2017-12-29 11:46:39; Journal ID: ISSN 1087-1845
Country of Publication:
United States

Citation Formats

Ao, Jie, and Free, Stephen J. Genetic and biochemical characterization of the GH72 family of cell wall transglycosylases in Neurospora crassa. United States: N. p., 2017. Web. doi:10.1016/j.fgb.2017.03.002.
Ao, Jie, & Free, Stephen J. Genetic and biochemical characterization of the GH72 family of cell wall transglycosylases in Neurospora crassa. United States. doi:10.1016/j.fgb.2017.03.002.
Ao, Jie, and Free, Stephen J. Sat . "Genetic and biochemical characterization of the GH72 family of cell wall transglycosylases in Neurospora crassa". United States. doi:10.1016/j.fgb.2017.03.002.
title = {Genetic and biochemical characterization of the GH72 family of cell wall transglycosylases in Neurospora crassa},
author = {Ao, Jie and Free, Stephen J.},
abstractNote = {},
doi = {10.1016/j.fgb.2017.03.002},
journal = {Fungal Genetics and Biology},
number = C,
volume = 101,
place = {United States},
year = {Sat Apr 01 00:00:00 EDT 2017},
month = {Sat Apr 01 00:00:00 EDT 2017}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1016/j.fgb.2017.03.002

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Cited by: 1work
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  • The qa-3 gene, one of the four genes in the qa gene cluster, encodes quinate (shikimate) dehydrogenase (quinate: NAD oxidoreductase, ER, the first enzyme in the inducible quinic acid catabolic pathway in Neurospora crassa. Genetic analyses have localized 26 qa-3 mutants at 11 sites on the qa-3 genetic map on the basis of prototroph frequencies. Certain mutants, e.g., 336-3-10 and 336-3-3, are located at opposite ends of the qa-3 gene. Data from four-point crosses (qa-1/sup S/ mutant 124 x five different qa-3 mutants in triple mutants qa-3, qa-4, qa-2) indicate the following orientation of the qa-3 gene within themore » qa cluster: qa-1, qa-3 mutant 336-3-10 (''left'' end) qa-3 mutant 336-3-3 (''right'' end), qa-4, qa-2. Ultraviolet-induced revertants have been obtained from 14 of the qa-3 mutants. The revertable mutants fall into two major classes: those that revert by changes either at the same site or at a second site within the qa-3 gene, and those that revert by unlinked suppressor mutations. The intragenic revertants can be further distinguished by quantitative and/or qualitative differences in their quinate dehydrogenase activities. Some revertants with activities either equivalent to or less than wild type produce a thermostable enzyme, and others an enzyme which is thermolabile in vitro at 35/sup 0/. A concentration of quinic acid or shikimic acid as low as 50 protects the enzyme markedly from heat inactivation. The genetic organization and the orientation of the qa-3 gene are discussed with respect to its direction of transcription and to the possible localization of a promoter (initiator) region(s) within the qa gene cluster.« less
  • Genetic and complementation mapping studies using 20 qa-2 mutants defective for catabolic dehydroquinase indicate that the qa-2 gene encodes a single polypeptide chain and is the structural gene for catabolic dehydroquinase, a 220,000-molecular-weight protein composed of identical 10,000-molecular-weight subunits. Many qa-2 mutants are capable of reversion, but no evidence has yet been obtained for nonsense mutations in this gene. The biochemical consequences of the mutations in two complementing qa-2 strains (M239 and M204) have been determined. Both mutants have extremely low levels of catalytic activity and form a heterocaryon with about 4 percent of the wild-type activity. As assayed bymore » immunological cross-reactivity, mutant M239 and the heterocaryon have nearly wild-type levels of native-molecular-weight catabolic dehydroquinase protein, whereas M204 has no detectable amount of this protein. Thus it is concluded that M239 has a mutation at or near the catalytic site which reduces the activity 10,000-fold but has little or no influence on the formation of the native multimeric structure. In contrast, M204 apparently has a mutation that severely inhibits aggregation and may have only a minor effect on the inherent potential for catalytic conversion at the reactive site. The heterocaryon would appear to form a mixed multimer with the monomeric subunits from M239 providing the aggregated structure and those from M204, the catalytically active moiety.« less
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