NAD kinase 2, mitochondrial; mitochondrial NAD kinase; NAD kinase domain-containing protein 1, mitochondrial (NADK2, C5orf33, MNADK, NADKD1)

Function

• mitochondrial NAD+ kinase
• phosphorylates NAD+ to yield NADP+
• can use both ATP or inorganic polyphosphate as the phosphoryl donor
• also has weak NADH kinase activity in vitro; however NADH kinase activity is much weaker than the NAD+ kinase activity & may not be relevant in vivo

ATP + NAD+ = ADP + NADP+

Kinetic parameters:

• KM=0.022 mM for NAD+
• KM=1.7 mM for ATP
• KM=1.2 mM for tetrapolyphosphate
• Vmax=0.091 umol/min/mg enzyme

Inhibition:

• inhibited by NADH, NADPH & NADP+

Structure

• homodimer (probable)
• belongs to the NAD kinase family

Compartment

mitochondria

Alternative splicing

named isoforms=3

Expression

widely expressed

More general terms

• mitochondrial protein
• kinase or ATP-phosphotransferase

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=133686
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:133686
• UniProt: http://www.uniprot.org/uniprot/Q4G0N4.html