These sequences represent the CopA copper resistance protein family. CopA is related to laccase (benzenediol:oxygen oxidoreductase) and L-ascorbate oxidase, both copper-containing enzymes. Most members have a typical TAT (twin-arginine translocation) signal sequence with an Arg-Arg pair. Twin-arginine translocation is observed for a large number of periplasmic proteins that cross the inner membrane with metal-containing cofactors already bound. The combination of copper-binding sites and TAT translocation motif suggests a mechanism of resistance by packaging and export.
CopA is a multicopper oxidase (MCO) related to laccase and L-ascorbate oxidase, both copper-containing enzymes [, ]. CopA mutant causes a loss of function including copper tolerance and oxidase activity and copA transcription is inducible in the presence of copper [].Although MCOs have diverse functions, majority of them have three cupredoxin domain repeats that include one mononuclear and one trinuclear copper centre. The copper ions are bound in several sites: Type 1, Type 2, and/or Type 3. The ensemble of types 2 and 3 copper is called a trinuclear cluster. MCOs oxidize their substrate by accepting electrons at a mononuclear copper centre and transferring them to the active site trinuclear copper centre. The cupredoxin domain 2 of 3-domain MCOs has lost the ability to bind copper [, , , ].
CopA is a multicopper oxidase (MCO) related to laccase and L-ascorbate oxidase, both copper-containing enzymes [, ]. CopA mutant causes a loss of function including copper tolerance and oxidase activity and copA transcription is inducible in the presence of copper [].Although MCOs have diverse functions, majority of them have three cupredoxin domain repeats that include one mononuclear and one trinuclear copper centre. The copper ions are bound in several sites: Type 1, Type 2, and/or Type 3. The ensemble oftypes 2 and 3 copper is called a trinuclear cluster. MCOs oxidize their substrate by accepting electrons at a mononuclear copper centre and transferring them to the active site trinuclear copper centre. The cupredoxin domain 1 of 3-domain MCOs contains part the trinuclear copper binding site, which is located at the interface of domains 1 and 3 [, , , ].
CopA is a multicopper oxidase (MCO) related to laccase and L-ascorbate oxidase, both copper-containing enzymes [, ]. CopA mutant causes a loss of function including copper tolerance and oxidase activity and copA transcription is inducible in the presence of copper [].Although MCOs have diverse functions, majority of them have three cupredoxin domain repeats that include one mononuclear and one trinuclear copper centre. The copper ions are bound in several sites: Type 1, Type 2, and/or Type 3. The ensemble of types 2 and 3 copper is called a trinuclear cluster. MCOs oxidize their substrate by accepting electrons at a mononuclear copper centre and transferring them to the active site trinuclear copper centre. The cupredoxin domain 3 of 3-domain MCOs contains the Type 1 (T1) copper binding site and part the trinuclear copper binding site, which is located at the interface of domains 1 and 3 [, , , ].
Proteins in this family are copper ion-binding proteins, including copper chaperone CopZ and COP-associated protein (COPP). They contain a conserved 30-residue HMA domain, which has been found in a number of other heavy metal transport or detoxification proteins []. CopZ is a chaperone that serves for the intracellular sequestration and transport of Cu+, and delivers copper ions to the copper-transporting ATPase CopA []. COPP is part of a cation-transporting system which is associated with copper export out of the cells [].
This entry represents the N-terminal HTH (helix-turn-helix) domain of YfmP and related proteins. YfmP is a a transcription regulator that regulates the multidrug efflux protein, YfmO, and indirectly regulates the expression of the Bacillus subtilis copZA operon encoding a metallochaperone, CopZ, and a CPx-type ATPase efflux protein, CopA []. These proteins belong to the MerR superfamily of transcription regulators that promote expression of several stress regulon genes by reconfiguring the spacer between the -35 and -10 promoter elements. Their conserved N-terminal domains contain predicted winged HTH motifs that mediate DNA binding, while the dissimilar C-terminal domains bind specific coactivator molecules [].
