Q72X44 · METAA_BACC1
- ProteinHomoserine O-acetyltransferase
- GenemetAA
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids301 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
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
- acetyl-CoA + L-homoserine = CoA + O-acetyl-L-homoserine
Kinetics
KM | SUBSTRATE | pH | TEMPERATURE[C] | NOTES | EVIDENCE | |
---|---|---|---|---|---|---|
185 μM | acetyl-CoA | |||||
214 μM | homoserine |
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.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Site | 111 | Important for acyl-CoA specificity | ||||
Sequence: E | ||||||
Active site | 142 | Acyl-thioester intermediate | ||||
Sequence: C | ||||||
Binding site | 163 | substrate | ||||
Sequence: K | ||||||
Binding site | 192 | substrate | ||||
Sequence: S | ||||||
Site | 192 | Important for substrate specificity | ||||
Sequence: S | ||||||
Active site | 235 | Proton acceptor | ||||
Sequence: H | ||||||
Active site | 237 | |||||
Sequence: E | ||||||
Binding site | 249 | substrate | ||||
Sequence: R |
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | cytoplasm | |
Molecular Function | homoserine O-acetyltransferase activity | |
Molecular Function | homoserine O-succinyltransferase activity | |
Biological Process | L-methionine biosynthetic process from homoserine via O-succinyl-L-homoserine and cystathionine |
Keywords
- Molecular function
- Biological process
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended nameHomoserine O-acetyltransferase
- EC number
- Short namesHAT
- Alternative names
Gene names
Organism names
- Strain
- Taxonomic lineageBacteria > Bacillota > Bacilli > Bacillales > Bacillaceae > Bacillus > Bacillus cereus group
Accessions
- Primary accessionQ72X44
Proteomes
Subcellular Location
Phenotypes & Variants
Features
Showing features for mutagenesis.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Mutagenesis | 47 | 17-fold increase in Km for acetyl-CoA and 14-fold decrease in catalytic activity. | ||||
Sequence: K → M | ||||||
Mutagenesis | 47 | 7-fold increase in Km for acetyl-CoA. | ||||
Sequence: K → R | ||||||
Mutagenesis | 111 | No activity with acetyl-CoA but catalyzes an acyltransferase reaction using succinyl-CoA and homoserine. | ||||
Sequence: E → G | ||||||
Mutagenesis | 142 | Lack of activity. | ||||
Sequence: C → A or S | ||||||
Mutagenesis | 163 | 13-fold increase in Km for homoserine. | ||||
Sequence: K → M | ||||||
Mutagenesis | 192 | 5-fold increase in Km for homoserine. | ||||
Sequence: S → A | ||||||
Mutagenesis | 235 | Lack of activity. | ||||
Sequence: H → A, N, or Q | ||||||
Mutagenesis | 237 | 65-fold decrease in catalytic activity. | ||||
Sequence: E → A | ||||||
Mutagenesis | 237 | 6-fold decrease in catalytic activity. | ||||
Sequence: E → D | ||||||
Mutagenesis | 237 | 19-fold decrease in catalytic activity. | ||||
Sequence: E → Q | ||||||
Mutagenesis | 249 | 64-fold increase in Km for homoserine and 10-fold decrease in catalytic activity. | ||||
Sequence: R → M |
PTM/Processing
Features
Showing features for chain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Chain | PRO_0000199736 | 1-301 | Homoserine O-acetyltransferase | |||
Sequence: MPIIIDKDLPARKVLQEENIFVMTKERAETQDIRALKIAILNLMPTKQETEAQLLRLIGNTPLQLDVHLLHMESHLSRNVAQEHLTSFYKTFRDIENEKFDGLIITGAPVETLSFEEVDYWEELKRIMEYSKTNVTSTLHICWGAQAGLYHHYGVQKYPLKEKMFGVFEHEVREQHVKLLQGFDELFFAPHSRHTEVRESDIREVKELTLLANSEEAGVHLVIGQEGRQVFALGHSEYSCDTLKQEYERDRDKGLNIDVPKNYFKHDNPNEKPLVRWRSHGNLLFSNWLNYYVYQETPYVL |
Interaction
Subunit
Homodimer.
Structure
Sequence
- Sequence statusComplete
- Length301
- Mass (Da)35,340
- Last updated2004-07-05 v1
- Checksum6476C52969F5067D
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
AE017194 EMBL· GenBank· DDBJ | AAS44434.1 EMBL· GenBank· DDBJ | Genomic DNA |