Amino acid sequence microheterogeneities of a type I cytokeratin of Mr 51 000 from Xenopus laevis epidermis

Abstract

The complete cDNA‐derived sequence of a type I cytokeratin (designated no. 3) from Xenopus laevis skin is described. The deduced protein has an M _r of 51 888 and consists of a glycine‐rich head domain, a well‐conserved α‐helical region and a tail rich in hydroxyamino acid residues. Various cDNA clones encoding two different mRNAs were isolated that differed by short deletions/insertions and point mutations. These microheterogeneities are mainly located in a ‘hypervariable region’ at the C‐terminal non‐α‐helical region.