Fig. 1. The Lama2^nmf417 mutation. (A-C) cDNA-sequence chromatograms from (A) wild-type, (B) heterozygous mutant nmf417 and (C) homozygous mutant nmf417 mice revealed mutation of T to C in the first position of codon 79 (arrowheads), which changes Cys79 to Arg (circled residue in C). Translation is shown above each chromatogram. (B) Intensities of the C- and T-containing sequences were similar in nmf417 heterozygotes, suggesting that the two transcripts were similarly abundant. (D) Alignment of laminin 2 peptide sequences from human, mouse and chicken, and their homologs in Drosophila and C. elegans, reveals phylogenetic conservation of Cys at this position (arrowhead). Residues identical to mouse are shown in red; peptide positions are shown at the right, provisional for the incomplete chick sequence (^*). (E) Cys79 in 2 is conserved in all laminin chains containing an LN domain. (F) Laminin 2 is a heterotrimer of the 2, β1 and 1 orthologs, with N-terminal portions separated and C-terminal portions entwined in a coiled-coil. LN domains at each N-terminus mediate aggregation. The chain ends in a series of LG domains, which bind to cell receptors. The nmf417 mutation is in the 2 LN domain.