Protein
Alpha-maltose-1-phosphate synthase
Organism
Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv)
Function
Involved in the biosynthesis of the maltose-1-phosphate (M1P) building block required for alpha-glucan production by the key enzyme GlgE (PubMed:18808383, PubMed:27513637). Catalyzes the formation of an alpha-1,4 linkage between glucose from ADP-glucose and glucose 1-phosphate (G1P) to yield maltose-1-phosphate (M1P) (PubMed:27513637). Also able to catalyze the elongation of the non-reducing ends of glycogen, maltodextrin and maltoheptaose using ADP-glucose as sugar donor, however the rate of the reaction appears to be too low to be physiologically relevant (PubMed:27513637). GlgM is also able to use UDP-glucose as sugar donor with G1P, however, it is less efficient than with ADP-glucose (PubMed:27513637). UDP-glucose is not used as sugar donor when glycogen is used as acceptor (PubMed:27513637).
Similarity
Belongs to the glycosyltransferase group 1 family.
Sequence
MRVAMLTREYPPEVYGGAGVHVTELVAYLRRLCAVDVHCMGAPRPGAFAYRPDPRLGSANAALSTLSADLVMANAASAATVVHSHTWYTALAGHLAAILYDIPHVLTAHSLEPLRPWKKEQLGGGYQVSTWVEQTAVLAANAVIAVSSAMRNDMLRVYPSLDPNLVHVIRNGIDTETWYPAGPARTGSVLAELGVDPNRPMAVFVGRITRQKGVVHLVTAAHRFRSDVQLVLCAGAADTPEVADEVRVAVAELARNRTGVFWIQDRLTIGQLREILSAATVFVCPSVYEPLGIVNLEAMACATAVVASDVGGIPEVVADGITGSLVHYDADDATGYQARLAEAVNALVADPATAERYGHAGRQRCIQEFSWAYIAEQTLDIYRKVCA