Kol-kväveligaser med glutamin som amid-N-givare
Glutamin
Kol-kväveligaser
Kol
Kväve
Ett gasformigt grundämne med kemiskt tecken N, atomnummer 7 och atomvikt 14. Kvävemolekylen består av en dubbelatom, och gasen utgör ca 78 volymprocent av jordens atmosfär. Kväve är en beståndsdel av proteiner och nukleinsyror, och ingår i alla levande celler.
Kol-kvävelyaser
Enzymer som katalyserar klyvning av kol-kvävebindningar på annat sätt än genom hydrolys eller oxidation. Undergrupper är ammoniaklyaser, amidinlyaser, aminlyaser och andra kol-kvävelyaser. EC 4.3.
Hydrolyaser
Ubikitin-proteinligaser
Ubiquitin-protein ligases are enzymes that play a crucial role in the ubiquitination process, which is a post-translational modification of proteins. This process involves the covalent attachment of the protein ubiquitin to specific lysine residues on target proteins, thereby marking them for degradation or altering their function, localization, or interaction with other proteins. Ubiquitin-protein ligases catalyze the transfer of ubiquitin from an E2 ubiquitin-conjugating enzyme to the target protein, forming an isopeptide bond between ubiquitin and the target protein. There are several classes of ubiquitin-protein ligases, including HECT (Homologous to the E6-AP Carboxyl Terminus), RING (Really Interesting New Gene), and U-box ligases, which differ in their mechanisms of catalyzing ubiquitination. Dysregulation of ubiquitin-protein ligases has been implicated in various diseases, including cancer, neurodegenerative disorders, and inflammatory conditions.
DNA-ligaser
Glutamatammoniakligas
SKP Cullin F-Box Protein Ligases
SCPH (Skp, Cullin, F-box containing) protein ligases are a family of E3 ubiquitin ligase complexes that play a crucial role in the ubiquitination and subsequent degradation of specific cellular proteins. These complexes are composed of three core components: Skp (S-phase kinase associated protein), Cullin, and an F-box protein. The F-box protein serves as a substrate recognition component that binds to the protein to be ubiquitinated, leading to its targeted degradation by the 26S proteasome. SCPH ligases are involved in various cellular processes, including cell cycle regulation, signal transduction, and DNA damage response.
Cullin Proteins
'Cullin proteins' are a family of structual components that play a crucial role in the formation of multi-subunit E3 ubiquitin ligase complexes, which are responsible for targeting specific cellular proteins for degradation via the ubiquitin-proteasome pathway. There are eight known mammalian cullin family members (CUL1, CUL2, CUL3, CUL4A, CUL4B, CUL5, CUL7, and CUL9), each of which associates with distinct sets of proteins to form unique E3 ubiquitin ligase complexes. These complexes regulate various cellular processes, including cell cycle progression, transcriptional regulation, DNA damage response, and signal transduction, by controlling the stability and function of key regulatory proteins through ubiquitination.
Glutaminas
Ett enzym som bryter ned glutamin genom reaktionen L-glutamin + H2O = L-glutamat + NH3. EC 3.5.1.2.
Ubiquitination
Ubiquitination är ett posttranslationellt modifieringssätt som involverar att en ubiquitinprotein kovalent adderas till en targetprotein. Detta process kontrolleras av tre huvudsakliga grupper av enzymkomplex: E1-ubiquitinaktiverande enzymer, E2-ubiquitinkonjugeringsenzymer och E3-ubiquitinligaseringsenzymer. Ubiquitiner kan adderas som en monomer eller i längre kedjor till targetproteinet, vilket kan leda till olika konsekvenser som proteasomdegradering, förändring av subcellulär lokalisation eller förändrad protein-proteininteraktion. Ubiquitination spelar därför en viktig roll i regleringen av cellulära processer såsom signaltransduktion, DNA-reparation och apoptos.