The domain within your query sequence starts at position 450 and ends at position 586; the E-value for the NDK domain shown below is 1.45e-33.

All catalytic sites are present in this domain. Check the literature (PubMed 95399390 ) for details.



SMART accession number:SM00562
Description: These are enzymes that catalyze nonsubstrate specific conversions of nucleoside diphosphates to nucleoside triphosphates. These enzymes play important roles in bacterial growth, signal transduction and pathogenicity.
Interpro abstract (IPR034907):

Nucleoside diphosphate kinases (EC (NDK) are enzymes required for the synthesis of nucleoside triphosphates (NTP) other than ATP. They provide NTPs for nucleic acid synthesis, CTP for lipid synthesis, UTP for polysaccharide synthesis and GTP for protein elongation, signal transduction and microtubule polymerisation.

NDK are proteins of 17 Kd that act via a ping-pong mechanism in which a histidine residue is phosphorylated, by transfer of the terminal phosphate group from ATP. In the presence of magnesium, the phosphoenzyme can transfer its phosphate group to any NDP, to produce an NTP.

NDK isozymes have been sequenced from prokaryotic and eukaryotic sources. It has also been shown [(PUBMED:2175255)] that the Drosophila awd (abnormal wing discs) protein, is a microtubule-associated NDK. Mammalian NDK is also known as metastasis inhibition factor nm23. The sequence of NDK has been highly conserved through evolution. There is a single histidine residue conserved in all known NDK isozymes, which is involved in the catalytic mechanism [(PUBMED:1851158)].

The enzyme is a hexamer composed by identical subunits with a novel mononucleotide binding fold. Each subunit contains an alpha/beta domain with a four stranded, anti-parallel beta-sheet [(PUBMED:556853)].

This alpha/beta domain is also found at the C terminus of retinitis pigmentosa 2 protein (XRP2/RP2) [(PUBMED:16472755)]. XRP2, a GTPase-activating protein, is required for maintenance of rod and cone photoreceptor cells in the retina [(PUBMED:26034134)].

Family alignment:
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There are 22429 NDK domains in 21229 proteins in SMART's nrdb database.

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