Riboflavin Kinase (RFK)

Riboflavin kinase (RFK; EC 2.7.1.26) is an essential enzyme that catalyzes the phosphorylation of riboflavin (vitamin B2) to form flavin mononucleotide (FMN), an obligatory step in vitamin B2 utilization and flavin cofactor synthesis.The reference genome sequence contains a polymorphism that changes the upstream ATG found in most transcripts to ATT; hence the next downstream AUG is annotated. This polymorphism is represented in the Reference SNP, rs2490582. The reference genome polymorphism results in a protein that is 7 aa shorter at the N-terminus, and is supported by homologous proteins. It is also possible that leaky scanning by ribosomes would permit translation initiation from the downstream AUG in alleles containing the upstream AUG.