Multiple sequence alignment of the derived amino acid sequence of RLK I. The derived amino acid sequence of RLK I [GenBank: EF156435] was aligned with the X. laevis type I keratin 47 kDa protein [GenBank: P05781] (Xl 47 kDa), a partial R. catesbeiana adult type I keratin RAK [GenBank: BAB47394.1] (RAK), the human type I keratin K19 [GenBank: NP_002267.2] (h K19), and the R. catesbeiana larval type II keratin RLK [GenBank: BAB47395] (RLK II) sequences. Gaps that were inserted for optimal alignment are indicated by a dash. Identical amino acids are shaded. Numbers indicate amino acid position for each sequence. The alignment was done using ClustalW software .