TITLE

Mechanisms underlying dioxygen reduction in laccases. Structural and modelling studies focusing on proton transfer

AUTHOR(S)
Bento, Isabel; Silva, Catarina S.; Zhenjia Chen; Martins, Lígia O.; Lindley, Peter F.; Soares, Cláudio M.
PUB. DATE
January 2010
SOURCE
BMC Structural Biology;2010, Vol. 10, p28
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
Background: Laccases are enzymes that couple the oxidation of substrates with the reduction of dioxygen to water. They are the simplest members of the multi-copper oxidases and contain at least two types of copper centres; a mononuclear T1 and a trinuclear that includes two T3 and one T2 copper ions. Substrate oxidation takes place at the mononuclear centre whereas reduction of oxygen to water occurs at the trinuclear centre. Results: In this study, the CotA laccase from Bacillus subtilis was used as a model to understand the mechanisms taking place at the molecular level, with a focus in the trinuclear centre. The structures of the holo-protein and of the oxidised form of the apo-protein, which has previously been reconstituted in vitro with Cu(I), have been determined. The former has a dioxygen moiety between the T3 coppers, while the latter has a monoatomic oxygen, here interpreted as a hydroxyl ion. The UV/visible spectra of these two forms have been analysed in the crystals and compared with the data obtained in solution. Theoretical calculations on these and other structures of CotA were used to identify groups that may be responsible for channelling the protons that are needed for reduction of dioxygen to water. Conclusions: These results present evidence that Glu 498 is the only proton-active group in the vicinity of the trinuclear centre. This strongly suggests that this residue may be responsible for channelling the protons needed for the reduction. These results are compared with other data available for these enzymes, highlighting similarities and differences within laccases and multicopper oxidases.
ACCESSION #
54106390

 

Related Articles

  • Application of a membrane bioreactor immobilized with Bacillus subtilis HHT-1 for removing manganese ions in water. K Takamizawa; Y C Chang; J Hattori; M Kani; K Mori; M Hatsu // Water Science & Technology: Water Supply;2001, Vol. 1 Issue 2, p183 

    A newly isolated Bacillus subtilis HHT-1 has the ability to oxidize manganese ions. We attempted to immobilize the cells on the microfiltration membrane and remove manganese ions from the raw water as manganese oxides. After subculturing, the broth was filtered with NTF-5200 (pore size 0.2...

  • sutilains.  // Taber's Cyclopedic Medical Dictionary (2009);2009, Issue 21, p2249 

    A definition of the term "sutilains," which refers to proteolytic enzymes derived from the bacterium Bacillus subtilis, is presented.

  • Development of marker-free strains of Bacillus subtilis capable of secreting high levels of industrial enzymes. Widner, B; Thomas, M; Sternberg, D; Lammon, D; Behr, R; Sloma, A // Journal of Industrial Microbiology & Biotechnology;Oct2000, Vol. 25 Issue 4, p204 

    Different strategies have been employed to achieve high-level expression of single-copy genes encoding secreted enzymes in Bacillus subtilis. A model system was developed which utilizes the aprL gene from Bacillus clausii as a reporter gene for monitoring expression levels during stationary...

  • Structure of the Bacillus subtilis d-aminopeptidase DppA reveals a novel self-compartmentalizing protease. Remaut, Han; Bompard-Gilles, Coralie; Goffin, Colette; Frère, Jean-Marie; Van Beeumen, Jozef // Nature Structural Biology;Aug2001, Vol. 8 Issue 8, p674 

    Bacillus subtilis DppA is a binuclear zinc-dependent, d-specific aminopeptidase. The X-ray structure of the enzyme has been determined at 2.4 Ã… resolution by a three-wavelength MAD experiment. The structure reveals that DppA is a new example of a 'self-compartmentalizing protease', a family...

  • Structural basis for the function of Bacillus subtilis phosphoribosyl-pyrophosphate synthetase. Eriksen, Tine A.; Kadziola, Anders; Bentsen, Ann-Kristin; Harlow, Kenneth W.; Larsen, Sine // Nature Structural Biology;Apr2000, Vol. 7 Issue 4, p303 

    Here we report the first three-dimensional structure of a phosphoribosylpyrophosphate (PRPP) synthetase. PRPP is an essential intermediate in several biosynthetic pathways. Structures of the Bacillus subtilis PRPP synthetase in complex with analogs of the activator phosphate and the allosteric...

  • Electrochemical synthesis of multi-armed CuO nanoparticles and their remarkable bactericidal potential against waterborne bacteria. Pandey, Pratibha; Merwyn, S.; Agarwal, G.; Tripathi, B.; Pant, S. // Journal of Nanoparticle Research;Jan2012, Vol. 14 Issue 1, p1 

    Copper (II) oxide multi-armed nanoparticles composed of 500-1000 nm long radiating nanospicules with 100-200 nm width near the base and 50-100 nm width at the tapered ends and ~25 nm thickness were synthesized by electrochemical deposition in the presence of an oxidant followed by calcination at...

  • The essential role of the Cu(II) state of Sco in the maturation of the Cu center of cytochrome oxidase: evidence from H135Met and H135SeM variants of the Bacillus subtilis Sco. Siluvai, Gnana; Nakano, Michiko; Mayfield, Mary; Blackburn, Ninian // Journal of Biological Inorganic Chemistry;Feb2011, Vol. 16 Issue 2, p285 

    Sco is a red copper protein that plays an essential yet poorly understood role in the metalation of the Cu center of cytochrome oxidase, and is stable in both the Cu(I) and Cu(II) forms. To determine which oxidation state is important for function, we constructed His135 to Met or...

  • Blocking Nitric Oxide May Give Antibiotics New Lease on Life. Breindl, Anette // BioWorld Today;9/11/2009, Vol. 20 Issue 175, p1 

    This article discusses a study published in the September 11, 2009 issue of "Science" which examined a way to boost the effectiveness of existing antibiotics. According to senior study author Evgeny Nudler, bacterial resistance is not an absolute thing. Two strains of Bacillus subtilis served as...

  • Aminoguanidine Down-Regulates the Expression of mreB-like Protein in Bacillus subtilis. Treece, Erin; Pinkham, Andrew; Kim, Thomas // Current Microbiology;Feb2012, Vol. 64 Issue 2, p112 

    Nitric oxide synthase (NOS), the enzyme responsible for the production of endogenous nitric oxide from arginine, has been recently discovered in a number of Gram-positive bacteria. While bacterial NOS has been implicated in mediating nitrosative stress, much remains unknown about the functional...

Share

Read the Article

Courtesy of VIRGINIA BEACH PUBLIC LIBRARY AND SYSTEM

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics