Methylmalonic aciduria cblB type (MMAB) gene, spanning 19.8kb length with 9 exons, is mapped to human chromosome 12q24.11. The gene codes for a 27.4kDa ATP cob (I) alamin adenosyltransferase (ATR) protein composed of 250 amino acids. The protein belongs to the family of PduO family of cobalamin...