Tektin B1 from ciliary microtubules : primary structure as deduced from the cDNA sequence and comparison with tektin A1

• Published in: Journal of cell science Vol. 106; no. 3; pp. 909 - 918
• Main Authors: RUNTIAN CHEN, PERRONE, C. A, AMOS, L. A, LINCK, R. W
• Format: Journal Article
• Language: English
• Published: Cambridge Company of Biologists 01.11.1993
• Subjects: Amino Acid Sequence; Animals; Base Sequence; Biological and medical sciences; Cilia - chemistry; Cloning, Molecular; DNA, Complementary - chemistry; Echinodermata; Fundamental and applied biological sciences. Psychology; Immunoblotting; Invertebrates; Microtubule Proteins - chemistry; Microtubule Proteins - genetics; Molecular Sequence Data; Protein Structure, Secondary; Sea Urchins; Sequence Homology, Amino Acid; Proteins; Marine environment; Strongylocentrotus purpuratus; Intermediary filament; Coiled structure; Echinodermata; Flagellum; Echinoidea; Microtubule; Invertebrata; Blastula; Centriole
• ISSN: 0021-9533; 1477-9137
• DOI: 10.1242/jcs.106.3.909

Tektins are a class of proteins that form filamentous polymers in the walls of ciliary and flagellar microtubules, and they may also be present in centrioles, centrosomes and mitotic spindles. We report here the cloning and sequencing of a cDNA for ciliary tektin B1. Comparison of the predicted amino acid sequence of tektin B1 with the previously published sequence for tektin A1 reveals several features that better define this class of proteins. Like tektin A1, the central region of the tektin B1 polypeptide chain is predicted to form a coiled-coil rod, consisting of four major alpha-helical regions that are separated by non-helical linkers. Between the central rod domains of tektins A and B there is a 34%/20% amino acid sequence identity/similarity, including equivalent 50-residue segments containing 36 identities, and a high probability of long-range structural homology. The tektin polypeptide chains are divided into two major segments that have significant sequence homology to each other, both within a given tektin chain and between tektins A and B, indicative of gene duplication events. The tektins have a secondary structure and molecular design similar to, but a low primary sequence homology with, intermediate filament proteins. Unlike tektin A1, tektin B1 lacks any part of the C-terminal IFP consensus sequence.