Q5SK28 · SPEE_THET8
- ProteinPolyamine aminopropyltransferase
- GenespeE
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids314 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
Function
function
Involved in the biosynthesis of polyamines which are thought to support the growth of thermophilic microorganisms under high-temperature conditions. It seems that long-chain and branched-chain of polyamines effectively stabilize DNA and RNA, respectively. Catalyzes the irreversible transfer of a propylamine group from the amino donor S-adenosylmethioninamine (decarboxy-AdoMet) to agmatine to yield N1-aminopropylagmatine. An efficient aminopropyltransferase activity has been also observed with norspermidine which produces thermine, and spermidine which produces spermine and thermospermine. The aminopropyl activity with homospermidine, mitsubishine, thermine, 1,3-diaminopropane, putrescine (1,4-diaminobutane), spermine and caldopentamine are very low. The reaction involves a nucleophilic attack on the C-3 methylene of the propylamine moiety adjacent to the positively charged sulfur of decarboxy-AdoMet.
Miscellaneous
In T.thermophilus, the biosynthetic pathways of spermidine operates via N1-aminopropylagmatine without the production of putrescine.
Catalytic activity
- agmatine + S-adenosyl 3-(methylsulfanyl)propylamine = H+ + N1-(3-aminopropyl)agmatine + S-methyl-5'-thioadenosine
Kinetics
KM | SUBSTRATE | pH | TEMPERATURE[C] | NOTES | EVIDENCE | |
---|---|---|---|---|---|---|
0.57 μM | norspermidine | 9 | 37 | |||
0.77 μM | agmatine | 9 | 37 | |||
1.64 μM | S-adenosylmethioninamine | 9 | 37 | |||
1.73 μM | spermidine | 9 | 37 | |||
38.3 μM | mitsubishine | 9 | 37 |
kcat is 0.73 sec-1 for aminopropyl transferase activity with S-adenosylmethioninamine as substrate (at pH 9 and 37 degrees Celsius). kcat is 0.65 sec-1 for aminopropyl transferase activity with spermidine as substrate (at pH 9 and 37 degrees Celsius). kcat is 0.53 sec-1 for aminopropyl transferase activity with norspermidine as substrate (at pH 9 and 37 degrees Celsius). kcat is 0.37 sec-1 for aminopropyl transferase activity with agmatine as substrate (at pH 9 and 37 degrees Celsius). kcat is 0.29 sec-1 for aminopropyl transferase activity with mitsubishine as substrate (at pH 9 and 37 degrees Celsius).
pH Dependence
Optimum pH is 8.5 at 60 degrees Celsius.
Temperature Dependence
Optimum temperature is above 80 degrees Celsius.
Features
Showing features for binding site, active site.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Binding site | 33 | S-methyl-5'-thioadenosine (UniProtKB | ChEBI) | ||||
Sequence: Q | ||||||
Binding site | 64 | spermidine (UniProtKB | ChEBI) | ||||
Sequence: H | ||||||
Binding site | 88 | spermidine (UniProtKB | ChEBI) | ||||
Sequence: E | ||||||
Binding site | 108 | S-methyl-5'-thioadenosine (UniProtKB | ChEBI) | ||||
Sequence: D | ||||||
Binding site | 140-141 | S-methyl-5'-thioadenosine (UniProtKB | ChEBI) | ||||
Sequence: DA | ||||||
Active site | 158 | Proton acceptor | ||||
Sequence: D | ||||||
Binding site | 158-161 | spermidine (UniProtKB | ChEBI) | ||||
Sequence: DLTD | ||||||
Binding site | 168 | S-methyl-5'-thioadenosine (UniProtKB | ChEBI) | ||||
Sequence: P |
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | cytoplasm | |
Molecular Function | agmatine aminopropyltransferase activity | |
Molecular Function | cadaverine aminopropyltransferase activity | |
Molecular Function | spermidine synthase activity | |
Molecular Function | spermine synthase activity | |
Molecular Function | thermospermine synthase activity | |
Biological Process | polyamine biosynthetic process | |
Biological Process | spermidine biosynthetic process |
Keywords
- Molecular function
- Biological process
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended namePolyamine aminopropyltransferase
- Alternative names
Gene names
Organism names
- Strain
- Taxonomic lineageBacteria > Deinococcota > Deinococci > Thermales > Thermaceae > Thermus
Accessions
- Primary accessionQ5SK28
- Secondary accessions
Proteomes
Subcellular Location
Phenotypes & Variants
Disruption phenotype
Cells lacking both speB and speE genes show defective growth at 70 degrees Celsius and significantly defective growth at 78 degrees Celsius. They accumulate agmatine and N1-aminopropylagmatine.
PTM/Processing
Features
Showing features for chain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Chain | PRO_1000012028 | 1-314 | Polyamine aminopropyltransferase | |||
Sequence: MDYGMYFFEHVTPYETLVRRMERVIASGKTPFQDYFLFESKGFGKVLILDKDVQSTERDEYIYHETLVHPAMLTHPEPKRVLIVGGGEGATLREVLKHPTVEKAVMVDIDGELVEVAKRHMPEWHQGAFDDPRAVLVIDDARAYLERTEERYDVVIIDLTDPVGEDNPARLLYTVEFYRLVKAHLNPGGVMGMQAGMILLTHHRVHPVVHRTVREAFRYVRSYKNHIPGFFLNFGFLLASDAFDPAAFSEGVIEARIRERNLALRHLTAPYLEAMFVLPKDLLEALEKETMVSTDQNPFYVTPEGEARQAPYKG |
Interaction
Subunit
Homotetramer.
Structure
Family & Domains
Features
Showing features for domain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Domain | 4-241 | PABS | ||||
Sequence: GMYFFEHVTPYETLVRRMERVIASGKTPFQDYFLFESKGFGKVLILDKDVQSTERDEYIYHETLVHPAMLTHPEPKRVLIVGGGEGATLREVLKHPTVEKAVMVDIDGELVEVAKRHMPEWHQGAFDDPRAVLVIDDARAYLERTEERYDVVIIDLTDPVGEDNPARLLYTVEFYRLVKAHLNPGGVMGMQAGMILLTHHRVHPVVHRTVREAFRYVRSYKNHIPGFFLNFGFLLASD |
Sequence similarities
Belongs to the spermidine/spermine synthase family.
Phylogenomic databases
Family and domain databases
Sequence
- Sequence statusComplete
- Length314
- Mass (Da)36,006
- Last updated2004-12-21 v1
- Checksum4B6E438CFE60552A
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
AP008226 EMBL· GenBank· DDBJ | BAD70647.1 EMBL· GenBank· DDBJ | Genomic DNA |