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PubMed · 8880933

Requirements for perpendicular helix pairing.

J R Beasley·G J Pielak
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Abstract

Cassette mutagenesis was used to produce a library of mutations at the interface of the N- and C-terminal helices of Saccharomyces cerevisiae iso-1-cytochrome c. The library is random and comprises > 98% mutations. Over 11,000 candidates were assayed for function by selecting for the ability of yeast, with the mutated gene as their sole cytochrome c source, to grow on nonfermentable carbon sources. We estimate that approximately 0.5% of the 160,000 total amino acid combinations at these four residues result in a functional cytochrome c. Significant correlations are found between the phenotype of yeast harboring the alleles and both the Dayhoff mutation matrix and transfer free energies (cyclohexane-to-water and n-octanol-to-water). Similar correlations are observed with respect to growth rate. Finally, sequences that are consistent with function follow a binary amino acid pattern.

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Amino Acid SequenceAmino AcidsBase SequenceCell DivisionCloning, MolecularCytochrome c GroupEscherichia coliGene ExpressionGene LibraryIsoenzymesModels, MolecularMolecular Sequence DataMutagenesis, InsertionalMutationPhenotypePlasmidsProtein Structure, SecondaryRestriction MappingSaccharomyces cerevisiaeJournal ArticleResearch Support, U.S. Gov't, P.H.S.

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J R Beasley, G J Pielak. 1996. Requirements for perpendicular helix pairing.. https://doi.org/10.1002/(sici)1097-0134(199609)26%3A1%3C95%3A%3Aaid-prot9%3E3.0.co%3B2-f

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