Q72X44 · METAA_BACC1

Function

function

Transfers an acetyl group from acetyl-CoA to L-homoserine, forming acetyl-L-homoserine. Utilizes a ping-pong kinetic mechanism in which the acetyl group of acetyl-CoA is initially transferred to the enzyme to form an acetyl-enzyme intermediate before subsequent transfer to homoserine to form the final product, O-acetylhomoserine. Cannot use succinyl-CoA as the acyl donor.

Catalytic activity

Kinetics

KM SUBSTRATE pH TEMPERATURE[C] NOTES EVIDENCE
185 μMacetyl-CoA
214 μMhomoserine
kcat is 58.6 min-1.

Pathway

Amino-acid biosynthesis; L-methionine biosynthesis via de novo pathway; O-acetyl-L-homoserine from L-homoserine: step 1/1.

Features

Showing features for site, active site, binding site.

TypeIDPosition(s)Description
Site111Important for acyl-CoA specificity
Active site142Acyl-thioester intermediate
Binding site163substrate
Binding site192substrate
Site192Important for substrate specificity
Active site235Proton acceptor
Active site237
Binding site249substrate

GO annotations

AspectTerm
Cellular Componentcytoplasm
Molecular Functionhomoserine O-acetyltransferase activity
Molecular Functionhomoserine O-succinyltransferase activity
Biological ProcessL-methionine biosynthetic process from homoserine via O-succinyl-L-homoserine and cystathionine

Keywords

Enzyme and pathway databases

Names & Taxonomy

Protein names

  • Recommended name
    Homoserine O-acetyltransferase
  • EC number
  • Short names
    HAT
  • Alternative names
    • Homoserine transacetylase
      (HTA
      )

Gene names

    • Name
      metAA
    • Synonyms
      metA
    • Ordered locus names
      BCE_5534

Organism names

Accessions

  • Primary accession
    Q72X44

Proteomes

Subcellular Location

Keywords

Phenotypes & Variants

Features

Showing features for mutagenesis.

TypeIDPosition(s)Description
Mutagenesis4717-fold increase in Km for acetyl-CoA and 14-fold decrease in catalytic activity.
Mutagenesis477-fold increase in Km for acetyl-CoA.
Mutagenesis111No activity with acetyl-CoA but catalyzes an acyltransferase reaction using succinyl-CoA and homoserine.
Mutagenesis142Lack of activity.
Mutagenesis16313-fold increase in Km for homoserine.
Mutagenesis1925-fold increase in Km for homoserine.
Mutagenesis235Lack of activity.
Mutagenesis23765-fold decrease in catalytic activity.
Mutagenesis2376-fold decrease in catalytic activity.
Mutagenesis23719-fold decrease in catalytic activity.
Mutagenesis24964-fold increase in Km for homoserine and 10-fold decrease in catalytic activity.

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_00001997361-301Homoserine O-acetyltransferase

Interaction

Subunit

Homodimer.

Family & Domains

Sequence similarities

Belongs to the MetA family.

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    301
  • Mass (Da)
    35,340
  • Last updated
    2004-07-05 v1
  • Checksum
    6476C52969F5067D
MPIIIDKDLPARKVLQEENIFVMTKERAETQDIRALKIAILNLMPTKQETEAQLLRLIGNTPLQLDVHLLHMESHLSRNVAQEHLTSFYKTFRDIENEKFDGLIITGAPVETLSFEEVDYWEELKRIMEYSKTNVTSTLHICWGAQAGLYHHYGVQKYPLKEKMFGVFEHEVREQHVKLLQGFDELFFAPHSRHTEVRESDIREVKELTLLANSEEAGVHLVIGQEGRQVFALGHSEYSCDTLKQEYERDRDKGLNIDVPKNYFKHDNPNEKPLVRWRSHGNLLFSNWLNYYVYQETPYVL

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
AE017194
EMBL· GenBank· DDBJ
AAS44434.1
EMBL· GenBank· DDBJ
Genomic DNA

Genome annotation databases

Similar Proteins

Disclaimer

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