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Characterization of Xenopus laevis complement factor I structure--conservation of modular structure except for an unusual insert not present in human factor I.

L M Kunnath-Muglia·G H Chang·R B Sim·A J Day·R A Ezekowitz
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Abstract

Factor I (C3b/C4b inactivator) is a regulatory protein of the classical and alternative complement pathways. In this paper, we report the sequence of Xenopus factor I cDNA and the deduced protein structure. The basic structure of human preprofactor I, NH2-heavy chain-cleavage peptide-light chain-COOH, is conserved in the frog. However, the frog heavy chain contains a highly charged segment of 29 amino acids, encoded by a poly dA-rich mRNA insert, which is not found in human factor I. The modular structure of the frog heavy chain was analyzed, and found to differ vis-à-vis previously published analyses of human factor I. We also evaluate the timing of factor I transcription during frog embryogenesis.

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Amino Acid SequenceAnimalsBase SequenceBlotting, NorthernChickensCloning, MolecularComplement Factor IDNAEmbryo, NonmammalianGene LibraryLampreysMaleMiceMolecular Sequence DataOligonucleotidesPolymerase Chain ReactionRNASequence AlignmentSequence Homology, Amino AcidTranscription, GeneticXenopus laevisComparative StudyJournal ArticleResearch Support, Non-U.S. Gov't

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L M Kunnath-Muglia, G H Chang, R B Sim, A J Day, R A Ezekowitz. 1993. Characterization of Xenopus laevis complement factor I structure--conservation of modular structure except for an unusual insert not present in human factor I.. https://doi.org/10.1016/0161-5890(93)90040-i

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