Protein Family Models

Members of this family include: purine nucleoside phosphorylase (PNP) Uridine phosphorylase (UdRPase) 5'-methylthioadenosine phosphorylase (MTA phosphorylase) [1]. 7920254. Unexpected sequence similarity between nucleosidases and phosphoribosyltransferases of different specificity. Mushegian AR, Koonin EV;. Protein Sci 1994;3:1081-1088. [2]. 9351810. The crystal structure of Escherichia coli purine nucleoside phosphorylase: a comparison with the human enzyme reveals a conserved topology. Mao C, Cook WJ, Zhou M, Koszalka GW, Krenitsky TA, Ealick SE;. Structure 1997;5:1373-1383. (from Pfam)

Date:

2024-10-16

nucleoside phosphorylase-I family protein| purine-nucleoside phosphorylase catalyzes the phosphorolysis of purine nucleoside to form the corresponding free purine base and pentose-1-phosphate

Date:

2017-03-02

This model represents the enzyme 5-methylthioadenosine/S-adenosylhomocysteine nucleosidase which acts on its two substrates at the same active site. This enzyme is involved in the recycling of the components of S-adenosylmethionine after it has donated one of its two non-ribose sulfur ligands to an acceptor. In the case of 5-methylthioadenosine this represents the first step of the methionine salvage pathway in bacteria [1,2,3]. This enzyme is widely distributed in bacteria, especially those that lack adenosylhomocysteinase (EC 3.3.1.1). One clade of bacteria including Agrobacterium, Mesorhizobium, Sinorhizobium and Brucella includes sequences annotated as MTA/SAH nucleotidase, but differs significantly in homology and has no independent experimental evidence. There are homologs of this enzyme in plants, some of which score between trusted and noise cutoffs here, but there is no experimental evidence to validate this function at this time.

Gene:

mtnN

Date:

2024-05-30

Date:

2020-10-26