title: Rv3868 (EccA1), an essential component of the Mycobacterium tuberculosis ESX-1 secretion system, is thermostable.
abstract: Rv3868 (EccA1) is an essential CbxX/CfqX-family ATPase of the Mycobacterium tuberculosis ESX-1 secretion system. Previously, we demonstrated that Rv3868 is composed of two domains; a regulatory N-terminal domain (NT-Rv3868) and an ATP binding C-terminal domain (CT-Rv3868). In the present report, chemical denaturation studies show that electrostatic interactions stabilize the Rv3868. Interestingly, Rv3868 has notable heat stability and retains about 50% of ATPase activity even at 60°C. The C-terminal domain was found to be important for the heat stability as demonstrated by both enzymatic activity assays and thermal denaturation experiments. Furthermore a structure-sequence analysis based on the content of charged and aliphatic amino acids rationalizes the higher propensity of Rv3868 for thermophilic characteristics.
authors: CSIR-Central Drug Research Institute, Mahatma Gandhi Marg, Lucknow, India.
authors: Amit
authors: A
authors: Luthra
authors: Amit
authors: A
authors: Gaur
authors: Ravishankar
authors: R
authors: Ramachandran
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry* / Q000378:metabolism*; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism*; D058947:Bacterial Secretion Systems; D008958:Models, Molecular; D009169:Mycobacterium tuberculosis / Q000378:metabolism*; D011489:Protein Denaturation; D017510:Protein Folding; D017434:Protein Structure, Tertiary; D055672:Static Electricity; D013696:Temperature
chemical_list: D001426:Bacterial Proteins; D058947:Bacterial Secretion Systems; D000251:Adenosine Triphosphatases