The structure of the small laccase from Streptomyces coelicolor reveals a link between laccases and nitrite reductases.
The X-ray structure of the two-domain laccase (small laccase) from Streptomyces coelicolor A3(2) was solved at 2.7-A resolution. The enzyme differs significantly from all laccases studied structurally so far. It consists of two domains and forms trimers and hence resembles the quaternary structure of nitrite reductases or ceruloplasmins more than that of large laccases. There are three trinuclear copper clusters in the enzyme localized between domains 1 and 2 of each pair of neighbor chains. In this way, a similar geometry of the active site as seen in large laccases is ensured, albeit by different arrangements of domains and protein chains. Three copper ions of type 1 lie close to one another near the surface of the central part of the trimer, and, effectively, a trimeric substrate binding site is formed in their vicinity.
Skálová
Tereza
T
Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, v.v.i., Heyrovského nám. 2, 162 06 Praha 6, Czech Republic. skalova@imc.cas.cz
Dohnálek
Jan
J
Østergaard
Lars Henrik
LH
Østergaard
Peter Rahbek
PR
Kolenko
Petr
P
Dusková
Jarmila
J
Stepánková
Andrea
A
Hasek
Jindrich
J
D000595:Amino Acid Sequence; D001204:Ascorbate Oxidase / Q000737:chemistry; D001665:Binding Sites; D002570:Ceruloplasmin / Q000737:chemistry; D003300:Copper / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D042845:Laccase / Q000737:chemistry*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D009572:Nitrite Reductases / Q000737:chemistry* / Q000378:metabolism; D055503:Protein Multimerization; D055550:Protein Stability; D020836:Protein Structure, Quaternary; D017433:Protein Structure, Secondary; D016415:Sequence Alignment; D012996:Solutions; D048372:Streptomyces coelicolor / Q000201:enzymology*; D013379:Substrate Specificity
D012996:Solutions; D003300:Copper; D042845:Laccase; D001204:Ascorbate Oxidase; D002570:Ceruloplasmin; D009572:Nitrite Reductases