Amino acid sequence of the carboxy-terminal part of an acidic type I cytokeratin of molecular weight 51 000 from Xenopus laevis epidermis as predicted from the cDNA sequence.
The DNA sequence of a clone from a cDNA library made from Xenopus laevis skin is described. This sequence represents the 3'-terminal end of an mRNA which codes for an epidermal cytokeratin polypeptide of mol. wt. 51 000 of the acidic (type I) subfamily as identified by hybridization-selection of mRNAs, followed by gel electrophoretic identification of the polypeptides synthesized by translation in vitro. The partial amino acid sequence of the amphibian cytokeratin shows strong similarity to type I cytoskeletal keratins from human (mol. wt. 50 000) and murine (mol. wt. 59 000) epidermis. In the non alpha-helical tail region the human and the non-mammalian (Xenopus) keratins are more similar to each other than to the murine protein, indicating that the former are equivalent cytokeratin polypeptides and belonging to a special subclass of type I keratin polypeptides devoid of glycine-rich regions in the carboxy-terminal portion. The evolutionary conservativity of the genes coding for cytokeratins is discussed.
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA / Q000032:analysis*; D004591:Electrophoresis, Polyacrylamide Gel; D007633:Keratins / Q000235:genetics* / Q000302:isolation & purification; D008970:Molecular Weight; D009693:Nucleic Acid Hybridization; D012333:RNA, Messenger / Q000235:genetics; D012867:Skin / Q000378:metabolism*; D014981:Xenopus
D012333:RNA, Messenger; D007633:Keratins; D004247:DNA