. 2017 May 5;8:714. doi: 10.3389/fpls.2017.00714

Table 2.

Conserved copper ligands in L1-L4 signature sequence.

Laccase	L1	L2	L3	L4
	`2 3`	`3 3`	`1 2 3`	`313 1 1`
SbLAC1	`90 $H$ W $H$ GLRQLRNGWADGPEFVTQCPI 113`	`130 GTLWW $H$ A $H$ SSWLRATVHGALIIHPRRG 156`	`499 $H$ PM $H$ I $H$ GY 506`	`561 $HCH$ IDA $H$ LTGG $L$ 572`
SbLAC2	`83 $H$ W $H$ GVRQLRTGWSDGPAYVTQCPI 106`	`123 GTLFW $H$ A $H$ VSWLRATLYGPIVILPKRG 149`	`477 $H$ PL $H$ L $H$ GF 484`	`539 $HCH$ LEV $H$ TSWG $L$ 550`
SbLAC3	–	–	`437 $H$ PV $H$ L $H$ GF 444`	`493 $HCH$ LDA $H$ LPFG $L$ 504`
SbLAC4	`86 $H$ W $H$ GVKQRLTCWADGAGMVTQCPI 109`	`126 GTLWW $H$ S $H$ VSILRATLHGIIIIRPKSG 152`	`494 NPM $H$ L $H$ G $H$ 501`	`556 $HCH$ FEF $H$ IAMG $M$ 567`
SbLAC5	`89 $H$ C $H$ GLKQRRNGWADGP———————— 104`	`107 GTLWW $H$ A $H$ IAWLRATVHGAVVVLPERG 133`	`397 $H$ PF $H$ L $H$ GY 404`	`459 $HCH$ LE—————G $L$ 465`
SbLAC6	`83 $H$ W $H$ GIRQMRTGWADGPEFVTQCPI 106`	`123 GTLWW $H$ A $H$ SSWLRATVYGGLIIRPREN 149`	`469 $H$ PI $H$ I $H$ GY 476`	`531 $HCH$ LDV $H$ ITWG $L$ 542`
SbLAC7	`85 $H$ W $H$ GIRQLRTGWADGPAYITQCPI 108`	`125 GTLWW $H$ A $H$ ISWLRATVYGPLVVLPKLG 151`	`480 $H$ PL $H$ L $H$ GF 487`	`542 $HCH$ LEV $H$ TTWG $L$ 553`
SbLAC8	`85 $H$ W $H$ GVRQLRSGWADGPAYITQCPI 108`	`125 GTLWW $H$ A $H$ ISWLRATVYGAIVILPKPG 151`	`480 $H$ PL $H$ L $H$ GF 487`	`542 $HCH$ LEV $H$ VSWG $L$ 553`
SbLAC9	`95 $H$ W $H$ GVRQLRNGWADGPAYITQCPI 118`	`135 GTLWW $H$ A $H$ FSWLRVHLYGPLVILPKRG 161`	`480 $H$ PL $H$ L $H$ GY 487`	`542 $HCH$ FDV $H$ LSWG $L$ 553`
SbLAC10	`80 $H$ W $H$ GVFQRGTPWADGPSMVTQCPI 103`	`120 GTLWW $H$ A $H$ SSFLRATVYGALIIRPRSG 146`	`466 $H$ PM $H$ L $H$ GF 473`	`530 $HCH$ IDA $H$ LTIG $L$ 541`
SbLAC11	`80 $H$ W $H$ GVLQLMTPWADGPSMVTQCPI 103`	`120 GTLWW $H$ A $H$ SSFLRATVYGAFIIRPRRG 146`	`450 $H$ PI $H$ L $H$ GF 457`	`510 $HCH$ LDP $H$ VPMG $L$ 521`
SbLAC12	`82 $H$ W $H$ GIFQLRSGWADGANMITQCPI 105`	`122 GTLWW $H$ A $H$ ASMLRATIYGALIIKPRNG 148`	`459 $H$ PI $H$ L $H$ GF 466`	`520 $HCH$ FDM $H$ LPLG $L$ 531`
SbLAC13	`89 $H$ W $H$ GVDQPRNPWSDGPEFITQCPI 112`	`129 GTLWW $H$ A $H$ SDFDRNTVHGAIVIRPRRG 155`	`492 $H$ PI $H$ L $H$ GF 499`	`554 $HCH$ FER $H$ MAWG $M$ 565`
SbLAC14	`101 $H$ W $H$ GVDQPRNPWSDGPEYITQCPI 124`	`141 GTLWW $H$ A $H$ SDFDRATVHGAIVIHPKRG 167`	`491 $H$ PM $H$ L $H$ GF 498`	`553 $HCH$ FDR $H$ TAWG $M$ 564`
SbLAC15	`87 $H$ W $H$ GVDQPRNPWSDGPEYITQCPI 110`	`127 GTLWW $H$ A $H$ SEFDRATVHGAIVIHPKRG 153`	`474 $H$ PM $H$ L $H$ GF 481`	`536 $HCH$ FDR $H$ TVWG $M$ 547`
SbLAC16	`111 $H$ W $H$ DVDQPRNPWSDGPEYITQCPI 134`	`151 GTLWW $H$ A $H$ SDFDRATVHGAVVIHPKHG 177`	`504 $H$ PM $H$ L $H$ GF 511`	`566 $HCH$ FDR $H$ TVWG $M$ 577`
SbLAC17	`103 $H$ W $H$ GVDQPRNPWFDGPEYITQCPI 126`	`143 GTLWW $H$ A $H$ SDFDRATVHGAIVIS———— 165`	`492 $H$ PM $H$ L $H$ GF 499`	`554 $HCH$ FNR $H$ MMWG $M$ 565`
SbLAC18	`96 $H$ W $H$ GVRQMRTGWSDGPEFVTQCPI 119`	`136 GTLWW $H$ A $H$ SSWLRATVHGALLIRPRAG 162`	`488 $H$ PI $H$ L $H$ GY 495`	`550 $HCH$ LDV $H$ ITWG $L$ 561`
SbLAC19	`93 $H$ W $H$ GVDQPRNPWSDGPEYITQCPI 116`	`133 GTLWW $H$ A $H$ SDFDRATVHGAIVVHPKRG 159`	`455 $H$ PM $H$ L $H$ GF 462`	`517 $HCH$ FD $H$ HTVWG $M$ 528`
SbLAC20	`95 $H$ W $H$ GVDQPRNPWSDGPE $H$ ITQCPI 118`	`135 GTLWW $H$ A $H$ SDYGRTTVHGVIVIRPKDD 161`	`475 $H$ PM $H$ L $H$ GY 482`	`537 $HCH$ IDI $H$ MVWG $M$ 548`
SbLAC21	`85 $H$ W $H$ GVRQLRSCWSDGAGFVTECPI 108`	`125 GTLWW $H$ A $H$ VTCLRATINGAFVIRPKDG 151`	`494 NPM $H$ LHGY 501`	`556 $HCH$ FEF $H$ IVMG $M$ 567`
SbLAC22	`87 $H$ W $H$ GVYQMRNCWNDGVPMVTQRPI 110`	`127 GTLWW $H$ A $H$ DAFLRGTIYGALIIRPRQG 153`	`499 NPM $H$ L $H$ GH 506`	`561 $HCH$ FEF $H$ LAMG $M$ 572`
SbLAC23	–	–	`254 $H$ PI $H$ L $H$ GY 261`	`286 $HCH$ LDV $H$ ITWG $L$ 297`
SbLAC24	`84 $H$ W $H$ GIFQRGTPWADGPTMVTQCPV 107`	`124 GTLWW $H$ A $H$ ISYLRATVYGALVLRPRGG 150`	`477 $H$ PM $H$ L $H$ GY 484`	`539 $HCH$ FDA $H$ LDLG $L$ 550`
SbLAC25	`89 $H$ W $H$ GVRQLRSGWSDGPSFITQCPI 112`	`129 GTLWW $H$ A $H$ FSWLRATLYGPLVILPPRG 155`	`486 $H$ PL $H$ L $H$ GY 493`	`548 $HCH$ LDV $H$ LSWG $L$ 559`
SbLAC26	`89 $H$ W $H$ GVRQLLSGWADGPSYITQCPI 112`	`129 GTLWW $H$ A $H$ ISWLRATVYGPIVILPPAG 155`	`486 $H$ PL $H$ L $H$ GF 493`	`548 $HCH$ LEV $H$ MSWG $L$ 559`
SbLAC27	`95 $H$ W $H$ GVDQPRNPWSDGPEYITQCPI 118`	`135 GTLWW $H$ A $H$ TGFDRATVHGAIVVLPRRG 161`	`506 $H$ PM $H$ L $H$ GF 513`	`568 $HCH$ FDR $H$ MVWG $M$ 579`

The equivalent signature sequences that distinguish S. bicolor laccases include L1, HWHGX₉DGX₅QCPI; L2, GTLWWHAHX₉GX₅PX₂G; L3, HPXHLHGX; L4, HLHX₃HX₃GX. The amino acids potentially involved in copper binding were highlighted in red, with numbers 1, 2, and 3 corresponding to Cu1, Cu2, and Cu3 ions.