Domain structure of selected LARP1 and La proteins and multiple-sequence alignment of LAMs. (A) Protein domain structure as defined by the National Center for Biotechnology Information Conserved domain finder (www.ncbi.nlm.nih.gov/Structure/cdd/wrpsb.cg). Motifs are depicted as boxes: black, LAM; light gray, RRM1; dark gray, RRM2; diagonally striped, RRM-L5; and vertically striped, DM15 motif. (B) Multiple sequence alignment of LAMs. The entire LAM of Slf1p and Sro9p comprised of 63 and 62 amino acids, respectively, is shown. Residues that are >80% conserved are boxed in gray. The identity and position of residues critical for terminal U binding in La proteins are shown on the top (numbering according to the Slf1 LAM). Asterisks highlight three aromatic amino acids that were changed to alanine in the Slf1 La-mutant. Species name abbreviations are as follows: S.c., Saccharomyces cerevisiae; C.e., Caenorhabditis elegans; D.m., Drosophila melanogaster; H.s., Homo sapiens; and T.b., Trypanosoma brucei.
