pMAL?系統(tǒng)是一種高效的蛋白融合表達(dá)及純化系統(tǒng)。pMAL載體含有編碼麥芽糖結(jié)合蛋白（Maltose Binding Protein, MBP）的大腸桿菌malE基因，其下游的多克隆位點(diǎn)便于目的基因插入，表達(dá)N端帶有MBP的融合蛋白。通過"tac"強(qiáng)啟動(dòng)子和malE翻譯起始信號(hào)使克隆基因獲得高效表達(dá)，并進(jìn)一步利用MBP對(duì)麥芽糖的親和性達(dá)到用Amylose柱對(duì)融合蛋白的一步親和純化。

The system uses the pMAL vectors which are designed so that insertion interrupts a lacZα gene allowing a blue-to-white screen for inserts on X-gal (5). pMAL-c2 series has an exact deletion of the malE signal sequence, resulting in cytoplasmic expression of the fusion protein. pMAL-p2 series contains the normal malE signal sequence, which directs the fusion protein through the cytoplasmic membrane. pMAL-p2 fusion proteins capable of being exported can be purified from the periplasm. Between the malE sequence and the polylinker there is a spacer sequence coding for 10 asparagine residues. This spacer insulates MBP from the protein of interest, increasing the chances that a particular fusion will bind tightly to the amylose resin. The vectors also include a sequence coding for the recognition site of a specific protease. This allows the protein of interest to be cleaved from MBP after purification, without adding any vector-derived residues to the protein (6). For this purpose, the polylinker includes a restriction site superimposed on the sequence coding for the site of the specific protease. This is where the gene of interest is inserted. An EcoR I site in the same reading frame as that of λgt11 and a number of other useful sites are present directly downstream. The vectors also include the M13 origin of DNA replication which allows the production of single-stranded DNA for sequencing and mutagenesis by infecting with M13KO7 helper phage (NEB #N0315S).

0001 CCGACACCAT CGAATGGTGC AAAACCTTTC GCGGTATGGC ATGATAGCGC CCGGAAGAGA 
0061 GTCAATTCAG GGTGGTGAAT GTGAAACCAG TAACGTTATA CGATGTCGCA GAGTATGCCG 
0121 GTGTCTCTTA TCAGACCGTT TCCCGCGTGG TGAACCAGGC CAGCCACGTT TCTGCGAAAA 
0181 CGCGGGAAAA AGTGGAAGCG GCGATGGCGG AGCTGAATTA CATTCCCAAC CGCGTGGCAC 
0241 AACAACTGGC GGGCAAACAG TCGTTGCTGA TTGGCGTTGC CACCTCCAGT CTGGCCCTGC 
0301 ACGCGCCGTC GCAAATTGTC GCGGCGATTA AATCTCGCGC CGATCAACTG GGTGCCAGCG 
0361 TGGTGGTGTC GATGGTAGAA CGAAGCGGCG TCGAAGCCTG TAAAGCGGCG GTGCACAATC 
0421 TTCTCGCGCA ACGCGTCAGT GGGCTGATCA TTAACTATCC GCTGGATGAC CAGGATGCCA 
0481 TTGCTGTGGA AGCTGCCTGC ACTAATGTTC CGGCGTTATT TCTTGATGTC TCTGACCAGA 
0541 CACCCATCAA CAGTATTATT TTCTCCCATG AAGACGGTAC GCGACTGGGC GTGGAGCATC 
0601 TGGTCGCATT GGGTCACCAG CAAATCGCGC TGTTAGCGGG CCCATTAAGT TCTGTCTCGG 
0661 CGCGTCTGCG TCTGGCTGGC TGGCATAAAT ATCTCACTCG CAATCAAATT CAGCCGATAG 
0721 CGGAACGGGA AGGCGACTGG AGTGCCATGT CCGGTTTTCA ACAAACCATG CAAATGCTGA 
0781 ATGAGGGCAT CGTTCCCACT GCGATGCTGG TTGCCAACGA TCAGATGGCG CTGGGCGCAA 
0841 TGCGCGCCAT TACCGAGTCC GGGCTGCGCG TTGGTGCGGA TATCTCGGTA GTGGGATACG 
0901 ACGATACCGA AGACAGCTCA TGTTATATCC CGCCGTTAAC CACCATCAAA CAGGATTTTC 
0961 GCCTGCTGGG GCAAACCAGC GTGGACCGCT TGCTGCAACT CTCTCAGGGC CAGGCGGTGA 
1021 AGGGCAATCA GCTGTTGCCC GTCTCACTGG TGAAAAGAAA AACCACCCTG GCGCCCAATA 
1081 CGCAAACCGC CTCTCCCCGC GCGTTGGCCG ATTCATTAAT GCAGCTGGCA CGACAGGTTT 
1141 CCCGACTGGA AAGCGGGCAG TGAGCGCAAC GCAATTAATG TAAGTTAGCT CACTCATTAG 
1201 GCACAATTCT CATGTTTGAC AGCTTATCAT CGACTGCACG GTGCACCAAT GCTTCTGGCG 
1261 TCAGGCAGCC ATCGGAAGCT GTGGTATGGC TGTGCAGGTC GTAAATCACT GCATAATTCG 
1321 TGTCGCTCAA GGCGCACTCC CGTTCTGGAT AATGTTTTTT GCGCCGACAT CATAACGGTT 
1381 CTGGCAAATA TTCTGAAATG AGCTGTTGAC AATTAATCAT CGGCTCGTAT AATGTGTGGA 
1441 ATTGTGAGCG GATAACAATT TCACACAGGA AACAGCCAGT CCGTTTAGGT GTTTTCACGA 
1501 GCACTTCACC AACAAGGACC ATAGCATATG AAAATAAAAA CAGGTGCACG CATCCTCGCA 
1561 TTATCCGCAT TAACGACGAT GATGTTTTCC GCCTCGGCTC TCGCCAAAAT CGAAGAAGGT 
1621 AAACTGGTAA TCTGGATTAA CGGCGATAAA GGCTATAACG GTCTCGCTGA AGTCGGTAAG 
1681 AAATTCGAGA AAGATACCGG AATTAAAGTC ACCGTTGAGC ATCCGGATAA ACTGGAAGAG 
1741 AAATTCCCAC AGGTTGCGGC AACTGGCGAT GGCCCTGACA TTATCTTCTG GGCACACGAC 
1801 CGCTTTGGTG GCTACGCTCA ATCTGGCCTG TTGGCTGAAA TCACCCCGGA CAAAGCGTTC 
1861 CAGGACAAGC TGTATCCGTT TACCTGGGAT GCCGTACGTT ACAACGGCAA GCTGATTGCT 
1921 TACCCGATCG CTGTTGAAGC GTTATCGCTG ATTTATAACA AAGATCTGCT GCCGAACCCG 
1981 CCAAAAACCT GGGAAGAGAT CCCGGCGCTG GATAAAGAAC TGAAAGCGAA AGGTAAGAGC 
2041 GCGCTGATGT TCAACCTGCA AGAACCGTAC TTCACCTGGC CGCTGATTGC TGCTGACGGG 
2101 GGTTATGCGT TCAAGTATGA AAACGGCAAG TACGACATTA AAGACGTGGG CGTGGATAAC 
2161 GCTGGCGCGA AAGCGGGTCT GACCTTCCTG GTTGACCTGA TTAAAAACAA ACACATGAAT 
2221 GCAGACACCG ATTACTCCAT CGCAGAAGCT GCCTTTAATA AAGGCGAAAC AGCGATGACC 
2281 ATCAACGGCC CGTGGGCATG GTCCAACATC GACACCAGCA AAGTGAATTA TGGTGTAACG 
2341 GTACTGCCGA CCTTCAAGGG TCAACCATCC AAACCGTTCG TTGGCGTGCT GAGCGCAGGT 
2401 ATTAACGCCG CCAGTCCGAA CAAAGAGCTG GCAAAAGAGT TCCTCGAAAA CTATCTGCTG 
2461 ACTGATGAAG GTCTGGAAGC GGTTAATAAA GACAAACCGC TGGGTGCCGT AGCGCTGAAG 
2521 TCTTACGAGG AAGAGTTGGC GAAAGATCCA CGTATTGCCG CCACTATGGA AAACGCCCAG 
2581 AAAGGTGAAA TCATGCCGAA CATCCCGCAG ATGTCCGCTT TCTGGTATGC CGTGCGTACT 
2641 GCGGTGATCA ACGCCGCCAG CGGTCGTCAG ACTGTCGATG AAGCCCTGAA AGACGCGCAG 
2701 ACTAATTCGA GCTCGAACAA CAACAACAAT AACAATAACA ACAACCTCGG GCCGGGTGCG 
2761 GCACACTACG TAGAATTCGG ATCCTCTAGA GTCGACCTGC AGGCAAGCTT GGCACTGGCC 
2821 GTCGTTTTAC AACGTCGTGA CTGGGAAAAC CCTGGCGTTA CCCAACTTAA TCGCCTTGCA 
2881 GCACATCCCC CTTTCGCCAG CTGGCGTAAT AGCGAAGAGG CCCGCACCGA TCGCCCTTCC 
2941 CAACAGTTGC GCAGCCTGAA TGGCGAATGG CAGCTTGGCT GTTTTGGCGG ATGAGATAAG 
3001 ATTTTCAGCC TGATACAGAT TAAATCAGAA CGCAGAAGCG GTCTGATAAA ACAGAATTTG 
3061 CCTGGCGGCA GTAGCGCGGT GGTCCCACCT GACCCCATGC CGAACTCAGA AGTGAAACGC 
3121 CGTAGCGCCG ATGGTAGTGT GGGGTCTCCC CATGCGAGAG TAGGGAACTG CCAGGCATCA 
3181 AATAAAACGA AAGGCTCAGT CGAAAGACTG GGCCTTTCGT TTTATCTGTT GTTTGTCGGT 
3241 GAACGCTCTC CTGAGTAGGA CAAATCCGCC GGGAGCGGAT TTGAACGTTG CGAAGCAACG 
3301 GCCCGGAGGG TGGCGGGCAG GACGCCCGCC ATAAACTGCC AGGCATCAAA TTAAGCAGAA 
3361 GGCCATCCTG ACGGATGGCC TTTTTGCGTT TCTACAAACT CTTTTTGTTT ATTTTTCTAA 
3421 ATACATTCAA ATATGTATCC GCTCATGAGA CAATAACCCT GATAAATGCT TCAATAATAT 
3481 TGAAAAAGGA AGAGTATGAG TATTCAACAT TTCCGTGTCG CCCTTATTCC CTTTTTTGCG 
3541 GCATTTTGCC TTCCTGTTTT TGCTCACCCA GAAACGCTGG TGAAAGTAAA AGATGCTGAA 
3601 GATCAGTTGG GTGCACGAGT GGGTTACATC GAACTGGATC TCAACAGCGG TAAGATCCTT 
3661 GAGAGTTTTC GCCCCGAAGA ACGTTCTCCA ATGATGAGCA CTTTTAAAGT TCTGCTATGT 
3721 GGCGCGGTAT TATCCCGTGT TGACGCCGGG CAAGAGCAAC TCGGTCGCCG CATACACTAT 
3781 TCTCAGAATG ACTTGGTTGA GTACTCACCA GTCACAGAAA AGCATCTTAC GGATGGCATG 
3841 ACAGTAAGAG AATTATGCAG TGCTGCCATA ACCATGAGTG ATAACACTGC GGCCAACTTA 
3901 CTTCTGACAA CGATCGGAGG ACCGAAGGAG CTAACCGCTT TTTTGCACAA CATGGGGGAT 
3961 CATGTAACTC GCCTTGATCG TTGGGAACCG GAGCTGAATG AAGCCATACC AAACGACGAG 
4021 CGTGACACCA CGATGCCTGT AGCAATGGCA ACAACGTTGC GCAAACTATT AACTGGCGAA 
4081 CTACTTACTC TAGCTTCCCG GCAACAATTA ATAGACTGGA TGGAGGCGGA TAAAGTTGCA 
4141 GGACCACTTC TGCGCTCGGC CCTTCCGGCT GGCTGGTTTA TTGCTGATAA ATCTGGAGCC 
4201 GGTGAGCGTG GGTCTCGCGG TATCATTGCA GCACTGGGGC CAGATGGTAA GCCCTCCCGT 
4261 ATCGTAGTTA TCTACACGAC GGGGAGTCAG GCAACTATGG ATGAACGAAA TAGACAGATC 
4321 GCTGAGATAG GTGCCTCACT GATTAAGCAT TGGTAACTGT CAGACCAAGT TTACTCATAT 
4381 ATACTTTAGA TTGATTTACC CCGGTTGATA ATCAGAAAAG CCCCAAAAAC AGGAAGATTG 
4441 TATAAGCAAA TATTTAAATT GTAAACGTTA ATATTTTGTT AAAATTCGCG TTAAATTTTT 
4501 GTTAAATCAG CTCATTTTTT AACCAATAGG CCGAAATCGG CAAAATCCCT TATAAATCAA 
4561 AAGAATAGAC CGAGATAGGG TTGAGTGTTG TTCCAGTTTG GAACAAGAGT CCACTATTAA 
4621 AGAACGTGGA CTCCAACGTC AAAGGGCGAA AAACCGTCTA TCAGGGCGAT GGCCCACTAC 
4681 GTGAACCATC ACCCAAATCA AGTTTTTTGG GGTCGAGGTG CCGTAAAGCA CTAAATCGGA 
4741 ACCCTAAAGG GAGCCCCCGA TTTAGAGCTT GACGGGGAAA GCCGGCGAAC GTGGCGAGAA 
4801 AGGAAGGGAA GAAAGCGAAA GGAGCGGGCG CTAGGGCGCT GGCAAGTGTA GCGGTCACGC 
4861 TGCGCGTAAC CACCACACCC GCCGCGCTTA ATGCGCCGCT ACAGGGCGCG TAAAAGGATC 
4921 TAGGTGAAGA TCCTTTTTGA TAATCTCATG ACCAAAATCC CTTAACGTGA GTTTTCGTTC 
4981 CACTGAGCGT CAGACCCCGT AGAAAAGATC AAAGGATCTT CTTGAGATCC TTTTTTTCTG 
5041 CGCGTAATCT GCTGCTTGCA AACAAAAAAA CCACCGCTAC CAGCGGTGGT TTGTTTGCCG 
5101 GATCAAGAGC TACCAACTCT TTTTCCGAAG GTAACTGGCT TCAGCAGAGC GCAGATACCA 
5161 AATACTGTCC TTCTAGTGTA GCCGTAGTTA GGCCACCACT TCAAGAACTC TGTAGCACCG 
5221 CCTACATACC TCGCTCTGCT AATCCTGTTA CCAGTGGCTG CTGCCAGTGG CGATAAGTCG 
5281 TGTCTTACCG GGTTGGACTC AAGACGATAG TTACCGGATA AGGCGCAGCG GTCGGGCTGA 
5341 ACGGGGGGTT CGTGCACACA GCCCAGCTTG GAGCGAACGA CCTACACCGA ACTGAGATAC 
5401 CTACAGCGTG AGCTATGAGA AAGCGCCACG CTTCCCGAAG GGAGAAAGGC GGACAGGTAT 
5461 CCGGTAAGCG GCAGGGTCGG AACAGGAGAG CGCACGAGGG AGCTTCCAGG GGGAAACGCC 
5521 TGGTATCTTT ATAGTCCTGT CGGGTTTCGC CACCTCTGAC TTGAGCGTCG ATTTTTGTGA 
5581 TGCTCGTCAG GGGGGCGGAG CCTATGGAAA AACGCCAGCA ACGCGGCCTT TTTACGGTTC 
5641 CTGGCCTTTT GCTGGCCTTT TGCTCACATG TTCTTTCCTG CGTTATCCCC TGATTCTGTG 
5701 GATAACCGTA TTACCGCCTT TGAGTGAGCT GATACCGCTC GCCGCAGCCG AACGACCGAG 
5761 CGCAGCGAGT CAGTGAGCGA GGAAGCGGAA GAGCGCCTGA TGCGGTATTT TCTCCTTACG 
5821 CATCTGTGCG GTATTTCACA CCGCATATAT GGTGCACTCT CAGTACAATC TGCTCTGATG 
5881 CCGCATAGTT AAGCCAGTAT ACACTCCGCT ATCGCTACGT GACTGGGTCA TGGCTGCGCC 
5941 CCGACACCCG CCAACACCCG CTGACGCGCC CTGACGGGCT TGTCTGCTCC CGGCATCCGC 
6001 TTACAGACAA GCTGTGACCG TCTCCGGGAG CTGCATGTGT CAGAGGTTTT CACCGTCATC 
6061 ACCGAAACGC GCGAGGCAGC TGCGGTAAAG CTCATCAGCG TGGTCGTGCA GCGATTCACA 
6121 GATGTCTGCC TGTTCATCCG CGTCCAGCTC GTTGAGTTTC TCCAGAAGCG TTAATGTCTG 
6181 GCTTCTGATA AAGCGGGCCA TGTTAAGGGC GGTTTTTTCC TGTTTGGTCA CTGATGCCTC 
6241 CGTGTAAGGG GGATTTCTGT TCATGGGGGT AATGATACCG ATGAAACGAG AGAGGATGCT 
6301 CACGATACGG GTTACTGATG ATGAACATGC CCGGTTACTG GAACGTTGTG AGGGTAAACA 
6361 ACTGGCGGTA TGGATGCGGC GGGACCAGAG AAAAATCACT CAGGGTCAAT GCCAGCGCTT 
6421 CGTTAATACA GATGTAGGTG TTCCACAGGG TAGCCAGCAG CATCCTGCGA TGCAGATCCG 
6481 GAACATAATG GTGCAGGGCG CTGACTTCCG CGTTTCCAGA CTTTACGAAA CACGGAAACC 
6541 GAAGACCATT CATGTTGTTG CTCAGGTCGC AGACGTTTTG CAGCAGCAGT CGCTTCACGT 
6601 TCGCTCGCGT ATCGGTGATT CATTCTGCTA ACCAGTAAGG CAACCCCGCC AGCCTAGCCG 
6661 GGTCCTCAAC GACAGGAGCA CGATCATGCG CACCCGTGGC CAGGACCCAA CGCTGCCCGA 
6721 AATT