Accepted name: N-terminal methionine Nα-acetyltransferase NatB
Reaction: (1) acetyl-CoA + an N-terminal L-methionyl-L-asparaginyl-[protein] = an N-terminal Nα-acetyl-L-methionyl-L-asparaginyl-[protein] + CoA
(2) acetyl-CoA + an N-terminal L-methionyl-L-glutaminyl-[protein] = an N-terminal Nα-acetyl-L-methionyl-L-glutaminyl-[protein] + CoA
(3) acetyl-CoA + an N-terminal L-methionyl-L-aspartyl-[protein] = an N-terminal Nα-acetyl-L-methionyl-L-aspartyl-[protein] + CoA
(4) acetyl-CoA + an N-terminal L-methionyl-L-glutamyl-[protein] = an N-terminal Nα-acetyl-L-methionyl-L-glutamyl-[protein] + CoA
Other name(s): NAA20 (gene name); NAA25 (gene name)
Systematic name: acetyl-CoA:N-terminal Met-Asn/Gln/Asp/Glu-[protein] Met-Nα-acetyltransferase
Comments: N-terminal acetylases (NATs) catalyse the covalent attachment of an acetyl moiety from acetyl-CoA to the free α-amino group at the N-terminus of a protein. This irreversible modification neutralizes the positive charge at the N-terminus and makes the N-terminal residue larger and more hydrophobic, and may also play a role in membrane targeting and gene silencing. The NatB complex is found in all eukaryotic organisms, and specifically targets N-terminal L-methionine residues attached to Asn, Asp, Gln, or Glu residues at the second position.
1.  Starheim, K.K., Arnesen, T., Gromyko, D., Ryningen, A., Varhaug, J.E. and Lillehaug, J.R. Identification of the human Nα-acetyltransferase complex B (hNatB): a complex important for cell-cycle progression. Biochem. J. 415 (2008) 325–331. [PMID: 18570629]
2.  Ferrandez-Ayela, A., Micol-Ponce, R., Sanchez-Garcia, A.B., Alonso-Peral, M.M., Micol, J.L. and Ponce, M.R. Mutation of an Arabidopsis NatB N-α-terminal acetylation complex component causes pleiotropic developmental defects. PLoS One 8:e80697 (2013). [PMID: 24244708]
3.  Lee, K.E., Ahn, J.Y., Kim, J.M. and Hwang, C.S. Synthetic lethal screen of NAA20, a catalytic subunit gene of NatB N-terminal acetylase in Saccharomyces cerevisiae. J Microbiol 52 (2014) 842–848. [PMID: 25163837]
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