Phylogenetic Distribution of CMP-Neu5Ac Hydroxylase (CMAH), the Enzyme Synthetizing the Proinflammatory Human Xenoantigen Neu5Gc

Peri, Sateesh; Kulkarni, Asmita; Feyertag, Felix; Berninsone, Patricia M; Alvarez-Ponce, David

We used all genomic data available from the NCBI Genome database to determine the occurrence of CMAH in nondeuterostomes. We then focused on the 321 deuterostome genomes and 2 echinoderm CMAH mRNA sequences available in the NCBI Genome database as of January 2017 (NCBI Coordinators 2016 ). An initial screening for the presence or absence of the CMAH gene was done using sequence similarity searches (BLASTP and TBLASTN searches) using the chimpanzee CMAH protein sequence as query. If BLASTP searches failed for a given organism (which depend on CMAH proteins being annotated), TBLASTN searches were conducted (which can detect unannotated sequences). All BLAST searches were performed using an E-value cut-off of 10 À10 (Altschul et al. 1990 ). All genomes, depending on the level of assembly, were either screened in the NCBI RefSeq genomic database (nonredundant, well-annotated reference sequence database) or in the NCBI WGS database (genome assemblies of incomplete genomes with or without annotation).