Function
Involved in the biosynthesis of the trisaccharide moiety characteristic of the antitumor drug aclacinomycins. In the first reaction, AknK catalyzes the transfer of 2-deoxy-beta-L-fucose from the activated donor dTDP-2-deoxy-beta-L-fucose to the mono-glycosylated aclacinomycin T (rhodosaminyl aklavinone), forming the di-glycosylated aclacinomycin S (L-2-deoxyfucosyl-L-rhodosaminyl aklavinone). It can also catalyze the addition of an alternate dTDP-L-sugar, dTDP-L-daunosamine, to aclacinomycin T and the addition of 2-deoxy-beta-L-fucose to the mono-glycosylated aglycones (monoglycosylated anthracyclines) such as daunomycin (daunorubicin), adriamycin (doxorubicin) and idarubicin. In vitro, AknK also catalyzes the addition of a second L-2-deoxyfucosyl moiety from dTDP-2-deoxy-beta-L-fucose, albeit with reduced activity, to the natural disaccharide chain of aclacinomycin S to produce L-deoxyfucosyl-L-deoxyfucosyl-L-rhodosaminyl aklavinone (2-deoxy-alpha-D-fucosyl-aclacinomycin S), a variant of the natural aclacinomycin A.
Sequence
MKVLFTTFAAKSHMHAQVPLAWALQTAGHEVRIASQPDLAEDITRTGLTAVCVGEPLLLEEQMQRVNEGLGDDAEIMESQAEAGMDMTETRPEMLTWDHVLGVFTSMTAMAFQNSCPERMIDDVVAFAREWQPDLIVWDTLSFAGPVAAQVTGAAHARLLFGLDLLGRMRETFLDLQEERLPEQRDDPLREWLTWTLGRYGAEFEEEVAVGQWTVDPVPPSMRFPVKQPFVPLRYIPYNGQAVIPDWLHEPPKKRRVCLTLGVAHREVLDGDRASIGELVEALAELDVEVVATLNEKQLAGMELPDNVRAVDFVPLNALLPTCSAVIHHGGSGTFQTALAHGVPQLIVPDMVWDTIHKAKQLERFGAGLYLHDVDNYTAQDLRDHLLRLLEEPSFAENCARIRREMVGTPSPNDIVPLLEKLTAEHRRDRGARGTVRGEQ