Function
Catalyzes the isomerization of ribose 1,5-bisphosphate (R15P) to ribulose 1,5-bisphosphate (RuBP), the CO(2) acceptor and substrate for RubisCO. Only accepts the alpha-anomer of D-ribose 1,5-bisphosphate as substrate, being inactive on the beta-anomer. Displays a strict substrate specificity, since other phosphorylated sugars such as R5P, ribose, G16P, G6P, G1P, FBP, F6P, and PRPP, are not substrates. Functions in an archaeal AMP degradation pathway, together with AMP phosphorylase and RubisCO.
Sequence
MAVVKEVLEIAEKIKNMEIRGAGKIARSAAYALQLQAEKSKATNVDEFWKEMKQAAKILFETRPTAVSLPNALRYVMHRGKIAYSSGADLEQLRFVIINAAKEFIHNSEKALERIGEFGAKRIEDGDVIMTHCHSKAAISVMKTAWEQGKDIKVIVTETRPKWQGKITAKELASYGIPVIYVVDSAARHYMKMTDKVVMGADSITVNGAVINKIGTALIALTAKEHRVWTMIAAETYKFHPETMLGQLVEIEMRDPTEVIPEDELKTWPKNIEVWNPAFDVTPPEYVDVIITERGIIPPYAAIDILREEFGWALKYTEPWED