||The plasmid MspA-M is designed for the preparation of a mutant Mycobacterium smegmatis porin A (MspA) nanopore, which is engineered with a methionine in the site of 91. Six extra histidine tag are designed for the followup purification using nickel affinity chromatography. MspA is a funnel-shaped, octameric channel protein which measures ~1.2 nm in diameter at its narrowest restriction, and its structure has been characterized using X-ray crystallography (PDB ID: 1uun). With a single, geometrically sharp restriction, MspA has an excellent performance in the DNA sequencing (Manrao E A, Derrington I M, Laszlo A H, et al. Nature biotechnology, 2012, 30(4): 349.; Laszlo A H, Derrington I M, Ross B C, et al. Nature biotechnology, 2014, 32(8): 829.). Rencently, the mutant of MspA (MspA-M) has been reported as a single-molecule nanoreactor for the detection of tetrachloroaurate(III) ions. Its sensing performance is superior to α-hemolysin (α-HL), which indicates that MspA is advantageous for single molecule chemistry investigations and has applications as a hybrid biological nanopore with atomic adaptors (Cao J, Jia W, Zhang J, et al. Nature Communications, 2019, 10(1): 1-11.).
||Cao, J., Jia, W., Zhang, J. et al. Giant single molecule chemistry events observed from a tetrachloroaurate(III) embedded Mycobacterium smegmatis porin A nanopore. Nat Commun 10, 5668 (2019) doi:10.1038/s41467-019-13677-2