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Split dnaE genes encoding multiple novel inteins in Trichodesmium erythraeum.

Xiang-Qin Liu·Jing Yang
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Abstract

Three inteins were found when analyzing a pair of split dnaE genes encoding the catalytic subunit of DNA polymerase III in the oceanic N2-fixing cyanobacterium Trichodesmium erythraeum. The three inteins (DnaE-1, DnaE-2, and DnaE-3) were clustered in a 70-amino acid (aa) region of the predicted DnaE protein. The DnaE-1 intein is 1258 aa long and three times as large as a typical intein, due to the presence of large tandem repeats in which a 57-aa sequence is repeated 17 times. The DnaE-2 intein has a more typical size of 428 aa with putative protein splicing and endonuclease domains. The DnaE-3 intein is a split intein consisting of a 102-aa N-terminal part and a 36-aa C-terminal part encoded on the first and second split dnaE genes, respectively. Synthesis of a mature DnaE protein is predicted to involve expression of two split dnaE genes followed by two protein cis-splicing reactions and one protein trans-splicing reaction. Tandem repeats in the DnaE-1 intein inhibited the protein splicing activity of this intein when tested in Escherichia coli cells and may potentially regulate DnaE synthesis in vivo.

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Amino Acid SequenceBase SequenceCyanobacteriaDNA Polymerase IIIDNA, BacterialGene ExpressionGenes, BacterialMolecular Sequence DataProtein SplicingSequence Homology, Amino AcidTandem Repeat SequencesJournal ArticleResearch Support, Non-U.S. Gov't

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Xiang-Qin Liu, Jing Yang. 2003-05-24. Split dnaE genes encoding multiple novel inteins in Trichodesmium erythraeum.. https://doi.org/10.1074/jbc.c300202200

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