TABLE 5.
Nucleotide/amino acid changes of mcr-1/MCR-1 alleles/variants compared with mcr-1.1/MCR-1.1 (the accession numbers emanated from Reference gene browser with gene family “mcr-1,” database version: 2020–05-04.1. Nucleotide and amino acid differences were identified by Geneious software).
| Allele/variant | RefSeq protein | Refseq nucleotide | GenBank protein | GenBank nucleotide | Nucleotide differences compared with mcr-1.1 | Amino acid differences compared with MCR-1.1 | First discovered host bacteria |
| mcr-1.1 | WP_049589868.1 | NG_050417.1 | AKF16168.1 | KP347127.1 | N/A | N/A | Escherichia coli |
| mcr-1.2 | WP_065274078.1 | NG_051170.1 | OBY14952.1 | LXQO01000025.1 | A8T | Gln3Leu | Klebsiella pneumoniae |
| mcr-1.3 | WP_077064885.1 | NG_052861.1 | ANJ15621.1 | KU934208.1 | AA111-112GG | Ile38Val | Escherichia coli |
| mcr-1.4 | WP_076611062.1 | NG_052664.1 | APM87143.1 | KY041856.1 | G1318A | Asp440Asn | Escherichia coli |
| mcr-1.5 | WP_076611061.1 | NG_052663.1 | APM84488.1 | KY283125.1 | C1354T | His452Tyr | Escherichia coli |
| mcr-1.6 | WP_077248208.1 | NG_052893.1 | AQK48217.1 | KY352406.1 | G1263A, G1607A | Arg536His | Salmonella enterica |
| mcr-1.7 | WP_085562392.1 | NG_054678.1 | AQQ11622.1 | KY488488.1 | G643A | Ala215Thr | Escherichia coli |
| mcr-1.8 | WP_085562407.1 | NG_054697.1 | AQY61516.1 | KY683842.1 | A8G | Gln3Arg | Escherichia coli |
| mcr-1.9a | WP_099982800.1 | NG_055582.1 | ASK38392.2 | KY964067.1 | T1238C | Val413Ala | Escherichia coli |
| mcr-1.10b | WP_096807442.1 | NG_055583.1 | ASK49940.1 | MF176238.1 | – | – | Moraxella sp. |
| mcr-1.11c | WP_099982815.1 | NG_055784.2 | ATM29809.1 | KY853650.2 | GTG19-21dup | Val7dup | Escherichia coli |
| mcr-1.12 | WP_104009850.1 | NG_056412.1 | BBB21811.1 | LC337668.1 | G9C | Gln3His | Escherichia coli |
| mcr-1.13 | WP_109545056.1 | NG_057466.1 | AVM85874.1 | MG384739.1 | G465A | Met155Ile | Escherichia coli |
| mcr-1.14 | WP_109545052.1 | NG_057460.1 | ARA74236.1 | KX443408.2 | AA111-112GG, G591A | Ile38Val, Met197Ile | Klebsiella pneumoniae |
| mcr-1.15d | WP_116786830.1 | NG_061610.1 | AXL06756.1 | MG763897.1 | AT1-2TA, C836A | Met1del, Thr279Lys | Klebsiella pneumoniae |
| mcr-1.16 | WP_136512110.1 | NG_064787.1 | QBG64271.1 | MK568462.1 | C952A | Arg318Ser | Escherichia coli |
| mcr-1.17 | WP_136512111.1 | NG_064788.1 | QBG64272.1 | MK568463.1 | G410C | Ser137Thr | Escherichia coli |
| mcr-1.18 | WP_106743337.1 | NG_064789.1 | – | PGLM01000025.1 | T25G | Tyr9Asp | Escherichia coli |
| mcr-1.19 | WP_129336087.1 | NG_065449.1 | QBC35984.1 | MK490674.1 | G1534A | Val512Ile | Salmonella enterica |
| mcr-1.20 | WP_140423329.1 | NG_065450.1 | SPQ84451.1 | LS398440.1 | A184C | Met62Leu | Escherichia coli |
| mcr-1.21 | WP_140423330.1 | NG_065451.1 | QCU55424.1 | MK965883.1 | C1234T | Pro412Ser | Escherichia coli |
| mcr-1.22 | WP_148044477.1 | NG_065944.1 | QDO71694.1 | MN017134.1 | C1277T | Ser426Phe | Escherichia coli |
| mcr-1.23e | WP_160164897.1 | NG_067235.1 | QHD57408.1 | MN873697.1 | – | – | Salmonella enterica |
| mcr-1.24f | WP_160164898.1 | NG_067236.1 | QHD64700.1 | MN879257.1 | – | – | Escherichia coli |
| mcr-1.25 | WP_160164899.1 | NG_067237.1 | QHD64702.1 | MN879259.1 | G41C, C565G | Ser14Thr, Leu189Val | Escherichia coli |
| mcr-1.26d | WP_034169413.1 | NG_068217.1 | NEU93872.1 | JAAGSA010000042.1 | T2C | Met1del | Escherichia coli |
| mcr-1.27 | WP_163397051.1 | NG_068218.1 | NEU89143.1 | JAAGSB010000042.1 | A26G | Tyr9Cys | Escherichia coli |
aUsing start codon that matches other mcr-1 genes rather than the one in the original INSDC entry. bDetails not listed for 39 nucleotide differences between mcr-1.10 and mcr-1.1 as well as 7 amino acid differences between MCR-1.10 and MCR-1.1. cDup, duplication of nucleotides/amino acids at positions indicated. dDel, deletion of amino acids at positions indicated. In comparison of mcr-1.1, the nucleotide at position 1 and 2 (AT) of mcr-1.15 mutate into TA, and also the nucleotide at position 2 (T) of mcr-1.26 mutate into C, resulting in a unavailable translation initiation codon of ATG at 1-3 and a retroposed codon from 4-6(ATG). eDetails not listed for 12 nucleotide differences between mcr-1.23 and mcr-1.1 as well as 9 amino acid differences between MCR-1.23 and MCR-1.1. fDetails not listed for 13 nucleotide differences between mcr-1.24 and mcr-1.1 as well as 10 amino acid differences between MCR-1.24 and MCR-1.1.