Combinatorial saturation mutagenesis of the Myceliophthora thermophila laccase T2 mutant: the connection between the C-terminal plug and the conserved 509VSG511 tripeptideShow others and affiliations
2008 (English)In: Combinatorial chemistry & high throughput screening, ISSN 1386-2073, E-ISSN 1875-5402, Vol. 11, no 10, p. 807-816Article in journal (Refereed) Published
Abstract [en]
A mutant laccase from the Ascomycete Myceliophthora thermophila has been submitted to iterative cycles of combinatorial satn. mutagenesis through in vivo overlap extension in Saccharomyces cerevisiae. Over 180,000 clones were explored, among which the S510G mutant revealed a direct interaction between the conserved 509VSG511 tripeptide, located in the neighborhood of the T1 site, and the C-terminal plug. The KmO2 value of the mutant increased 1.5-fold, and the electron transfer pathway between the reducing substrate and the T1 copper ion was altered, improving the catalytic efficiency towards non-phenolic and phenolic substrates by about 3- and 8-fold. Although the geometry at the T1 site was perturbed by the mutation, paradoxically the laccase redox potential was not significantly altered. Together, the results obtained in this study suggest that the 509VSG511 tripeptide may play a hitherto unrecognized role in regulating the traffic of oxygen through the C-terminal plug, the latter blocking access to the T2/T3 copper cluster in the native enzyme.
Place, publisher, year, edition, pages
Bentham Science Publishers Ltd. , 2008. Vol. 11, no 10, p. 807-816
Keywords [en]
Ascomycete laccases, C-terminal plug, combinatorial saturation mutagenesis, redox potential, Saccharomyces
National Category
Chemical Sciences
Identifiers
URN: urn:nbn:se:mau:diva-15041DOI: 10.2174/138620708786734235ISI: 000261495200004PubMedID: 19075602Scopus ID: 2-s2.0-57749085550Local ID: 6858OAI: oai:DiVA.org:mau-15041DiVA, id: diva2:1418562
2020-03-302020-03-302024-05-06Bibliographically approved