DNA gyrase subunit B (gyrB), partial, recombinant Escherichia coli

Organism: Escherichia coli (strain K12). Source: E.coli. Expression Region: 2-392aa. Protein Length: Partial. Tag Info: N-terminal 6xHis-tagged. Target Protein Sequence: SNSYDSSSIK VLKGLDAVRK RPGMYIGDTD DGTGLHHMVF EVVDNAIDEA LAGHCKEIIV TIHADNSVSV QDDGRGIPTG IHPEEGVSAA EVIMTVLHAG GKFDDNSYKV SGGLHGVGVS VVNALSQKLE LVIQREGKIH RQIYEHGVPQ APLAVTGETE KTGTMVRFWP SLETFTNVTE FEYEILAKRL RELSFLNSGV SIRLRDKRDG KEDHFHYEGG IKAFVEYLNK NKTPIHPNIF YFSTEKDGIG VEVALQWNDG FQENIYCFTN NIPQRDGGTH LAGFRAAMTR TLNAYMDKEG YSKKAKVSAT GDDAREGLIA VVSVKVPDPK FSSQTKDKLV SSEVKSAVEQ QMNELLAEYL LENPTDAKIV VGKIIDAARA REAARRAREM T. Purity: Greater than 95% as determined by SDS-PAGE. Endotoxin: Not test. Biological Activity: n/a. Form: Liquid or Lyophilized powder. Buffer: If the delivery form is liquid, the default storage buffer is Tris/PBS-based buffer, 5%-50% glycerol. If the delivery form is lyophilized powder, the buffer before lyophilization is Tris/PBS-based buffer, 6% Trehalose, pH 8.0. Reconstitution: We recommend that this vial be briefly centrifuged prior to opening to bring the contents to the bottom. Please reconstitute protein in deionized sterile water to a concentration of 0.1-1.0 mg/mL.We recommend to add 5-50% of glycerol (final concentration) and aliquot for long-term storage at -20°C/-80°C. Our default final concentration of glycerol is 50%. Customers could use it as reference. Storage: The shelf life is related to many factors, storage state, buffer ingredients, storage temperature and the stability of the protein itself. Generally, the shelf life of liquid form is 6 months at -20°C/-80°C. The shelf life of lyophilized form is 12 months at -20°C/-80°C. Notes: Repeated freezing and thawing is not recommended. Store working aliquots at 4°C for up to one week. Relevance: DNA gyrase negatively supercoils closed circular double-stranded DNA in an ATP-dependent manner to maintain chromosomes in an underwound state. This makes better substrates for topoisomerase 4 (ParC and ParE) which is the main enzyme that unlinks newly replicated chromosomes in E.coli. Gyrase catalyzes the interconversion of other topological isomers of double-stranded DNA rings, including catenanes. Relaxes negatively supercoiled DNA in an ATP-independent manner. E.coli gyrase has higher supercoiling activity than other characterized bacterial gyrases, at comparable concentrations E.coli gyrase introduces more supercoils faster than M.tuberculosis gyrase, while M.tuberculosis gyrase has higher decatenation than supercoiling activity compared to E.coli. E.coli makes 15% more negative supercoils in pBR322 plasmid DNA than S.typhimurium, the S.typhimurium GyrB subunit is toxic in E.coli, while the E.coli copy can be expressed in S.typhimurium even though the 2 subunits have 777/804 residues identical. The enzymatic differences between E.coli gyrase and topoisomerase IV are largely due to the GyrA C-terminal domain (approximately residues 524-841) and specifically the GyrA-box. Reference: n/a. Function: nan