Characteristic sequence features of the family of mosquito LRIM proteins. A. The annotated multiple sequence alignment of the Long LRIMs (LRIM1-4), the longest Coil-less LRIM (LRIM17), and the TM LRIMs (LRIM15-16) from Anopheles gambiae (Ag, red), Aedes aegypti (Aa, yellow), and Culex quinquefasciatus (Cq, purple). The alignment highlights the defining LRIM features including the signal peptide (SP), patterns of cysteine residues (C-C, C-CC, and C*), leucine-rich leader (LRL), leucine-rich repeats (LRRs a-n) and the double and single coiled-coil domains (dark, > 90% propensity, light < 90% propensity). The C-terminal transmembrane (TM) region identifies the TM LRIMs and the PANGGL (Pro-Ala-Asn-Gly-Gly-Leu) amino acid repeat is unique to Ag APL1C. Black diamonds indicate positions of a sequence frameshift in the gene encoding Ag APL1A and a transposable element insertion in the gene encoding Cq LRIM2A. B. Examining LRR length variations reveals different constraints on the lengths of sequences connecting the beta-strands that form the LRR horseshoe-like structure. The proportions of LRR lengths are shown for each set of aligned LRRs defined in Figure 3A (excluding those with only 3 or 4 representative sequences) and for those calculated from automated scanning of all 26 LRIMs shown in panel A (A), the complete proteomes of each of the three mosquito species (MS), and the proteomes of four other insects (IN, Apis mellifera, Bombyx mori, Drosophila melanogaster, and Tribolium castaneum). C. The conservation pattern of amino acid residues of the unusually short LRR-g (defined in panel A) is depicted in sequence logo format. The LRR signature is distinguished by the conserved asparagine (N) and leucines (L) (or the physicochemically similar isoleucines (I) and valines (V)), and proline (P) residues are common at positions 17 and 18 of LRR-g.