Difference between revisions of "Part:BBa K2384001"

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Lpp-OmpA-MBP(Pb)

Usage and Biology

It is well known that the structure of proteins determines its function.The two disulfide bond plays an important role in the folding and assembly of a structure with biological activity, and stability of this structure(Especially in containing more than one subunit protein or polypeptide).Disulfide bond formation protein A(DsbA) is folded enzyme catalyzed two sulfur bond formation in Escherichia coli periplasm cavity in a nascent protein folding process.It can greatly improve the folding rate of the nascent peptide chain, thus enabling Escherichia coli to ensure that the nascent polypeptide chains can be folded in a timely and correct fashion. DsbA is the first protein found in the Dsb family.It consists of 208 amino acids and has a C terminal signal peptide of 19 amino acids.It has an active central structure.The process of the formation and reduction of two sulfur bonds is achieved by exchanging sulfhydryl and two sulfur bonds between the active sites and the sulfhydryl or two sulfur bonds of the target proteins.(Thompson JD，Gibson TJ，Piewniak F，et a1．The ClustalX windows interface：flexible strategies for multiple sequence alignment aided by quality analysis tools．Nucleic Acids Research,1997,24:4876 -4882.) DsbA has a stronger oxidation than Thioredoxin.Experiments have shown that its strong oxidation comes from Cys30 residues with abnormally low pKa and unstable oxidation structure.(Zapun A,Cooper L,Creighton TE.Replacement of the active-site cysteine residues of DsbA, a protein required for disulfide bond formation in vivo.Biochemistry,1994,33:1907-1914.)Also, experimental results show that DsbA can improve the efficiency of protein folding in intracellular and extracellular.

PbrR is a member of the MerR family of metal-sensing regulatory protein, acts as an effective Pb(II) capturer. According to earlier research, the DNA binding domain and metal binding domain can function individually and the constructed peptide can form a stable dimer with its mercury and lead binding affinity remaining. In order to reduce side effects of over-expression, Peking University tandemed two copies of metal binding domain of PbrR.

Sequence and Features