|
|
|
ID:
41360.0,
MPI für Biochemie / Structure Research (R. Huber) |
Cytochrome c nitrite reductase from Desulfovibrio desulfuricans ATCC 27774 - The relevance of the two calcium sites in the structure of the catalytic subunit (NrfA) |
Authors: | Cunha, C. A.; Macieira, S.; Dias, J. M.; Almeida, G.; Goncalves, L. L.; Costa, C.; Lampreia, J.; Huber, R.; Moura, J. J. G.; Moura, I.; Romao, M. J. | Language: | English | Date of Publication (YYYY-MM-DD): | 2003-05-09 | Title of Journal: | Journal of Biological Chemistry | Journal Abbrev.: | J. Biol. Chem. | Volume: | 278 | Issue / Number: | 19 | Start Page: | 17455 | End Page: | 17465 | Review Status: | Peer-review | Audience: | Not Specified | Abstract / Description: | The gene encoding cytochrome c nitrite reductase (NrfA) from Desulfovibrio desulfuricans ATCC 27774 was sequenced and the crystal structure of the enzyme was determined to 2.3-Angstrom resolution. In comparison with homologous structures, it presents structural differences mainly located at the regions surrounding the putative substrate inlet and product outlet, and includes a well defined second calcium site with octahedral geometry, coordinated to propionates of hemes 3 and 4, and caged by a loop non-existent in the previous structures. The highly negative electrostatic potential in the environment around hemes 3 and 4 suggests that the main role of this calcium ion may not be electrostatic but structural, namely in the stabilization of the conformation of the additional loop that cages it and influences the solvent accessibility of heme 4. The NrfA active site is similar to that of peroxidases with a nearby calcium site at the heme distal side nearly in the same location as occurs in the class II and class III peroxidases. This fact suggests that the calcium ion at the distal side of the active site in the NrfA enzymes may have a similar physiological role to that reported for the peroxidases. | Comment of the Author/Creator: | Date: 2003, MAY 9 | External Publication Status: | published | Document Type: | Article |
Communicated by: | N.N. | Affiliations: | MPI für Biochemie/Structure Research (Huber)
| External Affiliations: | Univ Nova Lisboa, Fac Ciencias & Tecnol, Dept Quim, REQUIMTE; CQFB, P-2829516 Caparica, Portugal; Univ Nova Lisboa, Fac Ciencias & Tecnol, Dept Quim, REQUIMTE CQFB, P-2829516 Caparica, Portugal; Inst Super Ciencias Saude Sul, P-2825511 Caparica, Portugal
| Identifiers: | ISI:000182818600133 [ID No:1] ISSN:0021-9258 [ID No:2] | |
|
|
The scope and number of records on eDoc is subject
to the collection policies defined by each institute
- see "info" button in the collection browse view.
|
|