| IED ID | IndEnz0002015405 |
| Enzyme Type ID | protease015405 |
| Protein Name |
DNA-binding transcriptional activator HetR EC 3.4.21.- Heterocyst differentiation control protein |
| Gene Name | hetR alr2339 |
| Organism | Nostoc sp. (strain PCC 7120 / SAG 25.82 / UTEX 2576) |
| Taxonomic Lineage | cellular organisms Bacteria Terrabacteria group Cyanobacteria/Melainabacteria group Cyanobacteria Nostocales Nostocaceae Nostoc unclassified Nostoc Nostoc sp. (strain PCC 7120 / SAG 25.82 / UTEX 2576) |
| Enzyme Sequence | MSNDIDLIKRLGPSAMDQIMLYLAFSAMRTSGHRHGAFLDAAATAAKCAIYMTYLEQGQNLRMTGHLHHLEPKRVKIIVEEVRQALMEGKLLKTLGSQEPRYLIQFPYVWMEQYPWIPGRSRIPGTSLTSEEKRQIEHKLPSNLPDAQLVTSFEFLELIEFLHKRSQEDLPPEHRMELSEALAEHIKRRLLYSGTVTRIDSPWGMPFYALTRPFYAPADDQERTYIMVEDTARYFRMMKDWAEKRPNAMRALEELDVPPERWDEAMQELDEIIRTWADKYHQVGGIPMILQMVFGRKED |
| Enzyme Length | 299 |
| Uniprot Accession Number | P27709 |
| Absorption | |
| Active Site | ACT_SITE 152; /evidence="ECO:0000255|HAMAP-Rule:MF_00781, ECO:0000269|PubMed:10692362" |
| Activity Regulation | ACTIVITY REGULATION: Protease activity is inhibited by PMSF, suggesting this is a serine protease. {ECO:0000269|PubMed:9560210}. |
| Binding Site | |
| Calcium Binding | |
| catalytic Activity | |
| DNA Binding | |
| EC Number | 3.4.21.- |
| Enzyme Function | FUNCTION: Controls heterocyst differentiation. Dimerization is required for DNA-binding. Has both a protease and a DNA-binding activity. {ECO:0000255|HAMAP-Rule:MF_00781}.; FUNCTION: Controls heterocyst differentiation; increased expression leads to more heterocysts than usual (PubMed:1840555). Has protease activity (PubMed:9560210). Binds the promoter regions of hetR, hepA and patS and is required for their expression. Dimerization is required for DNA-binding, DNA-binding is inhibited by the PatS6 peptide (PubMed:15051891). In Nostoc filaments, approximately every 10th vegetative cell terminally differentiates into a heterocyst specialized for nitrogen fixation (PubMed:8412673, PubMed:10692362, PubMed:15051891). {ECO:0000269|PubMed:10692362, ECO:0000269|PubMed:15051891, ECO:0000269|PubMed:1840555, ECO:0000269|PubMed:8412673, ECO:0000269|PubMed:9560210}. |
| Temperature Dependency | |
| PH Dependency | |
| Pathway | |
| nucleotide Binding | NP_BIND 34..40; /note=DNA; /evidence=ECO:0000269|PubMed:26576507; NP_BIND 60..76; /note=DNA; /evidence=ECO:0000269|PubMed:26576507; NP_BIND 179..181; /note=DNA; /evidence=ECO:0000269|PubMed:26576507 |
| Features | Active site (1); Beta strand (8); Chain (1); Disulfide bond (1); Helix (14); Mutagenesis (11); Nucleotide binding (3); Region (3); Turn (1) |
| Keywords | 3D-structure;Activator;Autocatalytic cleavage;DNA-binding;Direct protein sequencing;Disulfide bond;Heterocyst;Hydrolase;Protease;Reference proteome;Serine protease;Transcription;Transcription regulation |
| Interact With | Itself |
| Induction | INDUCTION: By nitrogen deficiency (at protein level). Activates its own expression (PubMed:10692362, PubMed:1840555, PubMed:8412673). Transcription increases quickly upon nitrogen reduction and remains high during heterocyst differentiation (at least 24 hours). Transcription is blocked by the C-terminal PatS peptide (sequence Arg-Gly-Ser-Gly-Arg) (PubMed:15051891). {ECO:0000269|PubMed:10692362, ECO:0000269|PubMed:15051891, ECO:0000269|PubMed:1840555, ECO:0000269|PubMed:8412673, ECO:0000269|Ref.3}. |
| Subcellular Location | |
| Modified Residue | |
| Post Translational Modification | PTM: Probably autodegrades. {ECO:0000305|PubMed:10692362, ECO:0000305|PubMed:9560210}. |
| Signal Peptide | |
| Structure 3D | X-ray crystallography (4) |
| Cross Reference PDB | 4HRI; 4LH9; 4YNL; 4YRV; |
| Mapped Pubmed ID | - |
| Motif | |
| Gene Encoded By | |
| Mass | 34,969 |
| Kinetics | |
| Metal Binding | |
| Rhea ID | |
| Cross Reference Brenda |