Accession | TIGR00656 |
Name | asp_kin_monofn |
Function | aspartate kinase, monofunctional class |
Trusted Cutoff | 402.25 |
Domain Trusted Cutoff | 402.25 |
Noise Cutoff | 355.20 |
Domain Noise Cutoff | 355.20 |
Isology Type | equivalog |
EC Number | 2.7.2.4 |
HMM Length | 407 |
Mainrole Category | Amino acid biosynthesis |
Subrole Category | Aspartate family |
Gene Ontology Term | GO:0004072: aspartate kinase activity molecular_function |
| GO:0009089: lysine biosynthetic process via diaminopimelate biological_process |
Author | Haft DH |
Entry Date | Dec 1 1999 10:45AM |
Last Modified | Feb 25 2011 12:36PM |
Comment | This model describes a subclass of aspartate kinases. These are mostly Lys-sensitive and not fused to homoserine dehydrogenase, unlike some Thr-sensitive and Met-sensitive forms. Homoserine dehydrogenase is part of Thr and Met but not Lys biosynthetic pathways.
Aspartate kinase catalyzes a first step in the biosynthesis from Asp of Lys (and its precursor diaminopimelate), Met, and Thr. In E. coli, a distinct isozyme is inhibited by each of the three amino acid products. The Met-sensitive (I) and Thr-sensitive (II) forms are bifunctional enzymes fused to homoserine dehydrogenases and form homotetramers, while the Lys-sensitive form (III) is a monofunctional homodimer.
The Lys-sensitive enzyme of Bacillus subtilis resembles the E. coli form but is an alpha 2/beta 2 heterotetramer, where the beta subunit is translated from an in-phase alternative initiator at Met-246. The protein slr0657 from Synechocystis PCC6803 is extended by a duplication of the C-terminal region corresponding to the beta chain. Incorporation of a second copy of the C-terminal domain may be quite common in this subgroup of aspartokinases. |
References | A2 hmmalign
GA hmmsearch
AL clustalw_manual
DR EXPERIMENTAL; EGAD|9629|EC4024; monofunctional, Lys-sensitive homodimer
DR EXPERIMENTAL; EGAD|15096|BS2841; monofunctional, Lys-sensitive heterotetramer
DR EXPERIMENTAL; EGAD|24158|BS1676; monofunctional, diaminopimelate-sensitive heterotetramer
DR OUTGROUP; EGAD|9487|EC0002; bifunctional, Thr-sensitive homotetramer
DR OUTGROUP; EGAD|21696|EC3940; bifunctional, Met-sensistive homotetramer
DR OUTGROUP; EGAD|52194|YER052C; mostly Thr-sensitive
DR OUTGROUP; EGAD|75283|81007; bifunctional, chloroplast |
Genome Property | GenProp0160: aspartate semialdehyde biosynthesis from aspartate (HMM) |