Fig. 7: Identification of SNYG modules in C. reinhardtii and mammalian MIPs.

a Multiple sequence alignment of the SNYG module in eight human proteins identified by iterative HMM-to-HMM searches. The SNYG module consists of two α-helices, one representing the conserved Mn repeat-like motif bearing a highly conserved glycine, and the other helix here named the SNYG motif associated helix (SNYG ass. helix). Proteins are designated by their UniProt identifiers. Coloring schemes as per ClustalW parameters with modifications. Predicted regions corresponding to α-helices are shown above the alignment. b Superimposition of experimentally determined SNYG modules from mammalian PIERCE1, PIERCE2, TEX49, FAM183A, C5ORF49 (CFAP90), and ATP6V1FNB (SPMIP1). Structures were derived from PDB: 8OTZ. c Module architecture of predicted SNYG module proteins in human. d The SNYG module in FAP85 and FAP182 (shown in boxes) in complex with the tubulin lattice of the C. reinhardtii cilia outer doublet A-tubule (PDB: 6U42). Protofilament number shown right. e Superimposition of SNYG module structures from FAP85 and FAP182. f Superimpositions of FAP182 SNYG module structures with AlphaFold2-predicted SNYG modules of PIERCE1 and PIERCE2. g The FAP85 SNYG modules in complex with tubA and tubB. Contact sites between tubulins and conserved threonine or hydrophobic residues are highlighted in red. h GO enrichment of gene co-expression analysis (top 6) of the four SNYG family members C20ORF85, C2ORF50, C5ORF49, and FAM183A. Enrichment P-values were obtained using the PANTHER Classification System for the slim cellular component devised by the PANTHER software⁵⁷. i Immunofluorescence microscopy micrographs of motile cilia on cultured human bronchial epithelial cells imaged by structured illumination microscopy. Cells were stained with indicated antibodies. The images are representative of two independent experiments. Scale bar: 5 μm in the top row, 500 nm in the second row.