6ihg
N terminal domain of Mycobacterium avium complex Lon protease
Structural highlights
FunctionA0A051TYQ1_9MYCO ATP-dependent serine protease that mediates the selective degradation of mutant and abnormal proteins as well as certain short-lived regulatory proteins. Required for cellular homeostasis and for survival from DNA damage and developmental changes induced by stress. Degrades polypeptides processively to yield small peptide fragments that are 5 to 10 amino acids long. Binds to DNA in a double-stranded, site-specific manner.[HAMAP-Rule:MF_01973][SAAS:SAAS00004329] Publication Abstract from PubMedLon protease is evolutionarily conserved in prokaryotes and eukaryotic organelles. The primary function of Lon is to selectively degrade abnormal and certain regulatory proteins to maintain the homeostasis in vivo. Lon mainly consists of three functional domains and the N-terminal domain is required for the substrate selection and recognition. However, the precise contribution of the N-terminal domain remains elusive. Here, we determined the crystal structure of the N-terminal 192-residue construct of Lon protease from Mycobacterium avium complex at 2.4 a resolutionand measured NMR-relaxation parameters of backbones. This structure consists of two subdomains, the beta-strand rich N-terminal subdomain and the five-helix bundle of C-terminal subdomain, connected by a flexible linkerand is similar to the overall structure of the N domain of E. coli Lon even though their sequence identity is only 26%. The obtained NMR-relaxation parameters reveal two stabilized loops involving in the structural packing of the compact N domain and a turn structure formation. The performed homology comparison suggests that structural and sequence variations in the N domain may be closely related to the substrate selectivity of Lon variants. Our results provide the structure and dynamics characterization of a new Lon N domain, and will help to define the precise contribution of the Lon N-terminal domain to the substrate recognition. Crystal structure of the N domain of Lon protease from Mycobacterium avium complex.,Chen X, Zhang S, Bi F, Guo C, Feng L, Wang H, Yao H, Lin D Protein Sci. 2019 Jul 15. doi: 10.1002/pro.3687. PMID:31306520[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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