Structural Determinants in the Group III Truncated Hemoglobin from Campylobacter jejuni
| Autor: | Alessandro Bolli, Marco Nardini, Paolo Ascenzi, Michel Guertin, Alessandra Pesce, Marie LaBarre, Christian Richard, Martino Bolognesi |
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| Přispěvatelé: | Nardini, M, Pesce, A, Labarre, M, Richard, C, Bolli, A, Ascenzi, Paolo, Guertin, M, Bolognesi, M. |
| Rok vydání: | 2006 |
| Předmět: |
DNA
Bacterial Models Molecular Protein Folding Molecular Sequence Data Heme Crystallography X-Ray Biochemistry Campylobacter jejuni Protein Structure Secondary Hemoglobins chemistry.chemical_compound Bacterial Proteins Eubacterium Amino Acid Sequence Globin Molecular Biology Base Sequence Molecular Structure Sequence Homology Amino Acid biology OXYGEN-METABOLISM CYANIDE BINDING Truncated Hemoglobins MYCOBACTERIUM-TUBERCULOSIS HEMOGLOBIN Cell Biology biology.organism_classification Recombinant Proteins Protein Structure Tertiary Globin fold Myoglobin chemistry LIGAND-BINDING X-RAY Hemoglobin Sequence motif |
| Zdroj: | 281 (2006): 37803–37812. info:cnr-pdr/source/autori:Nardini, M; Pesce, A; Labarre, M; Richard, C; Bolli, A; Ascenzi, P; Guertin, M; Bolognesi, M/titolo:Structural determinants in the group III truncated hemoglobin from Campylobacter jejuni/doi:/rivista:/anno:2006/pagina_da:37803/pagina_a:37812/intervallo_pagine:37803–37812/volume:281 |
| ISSN: | 0021-9258 |
| DOI: | 10.1074/jbc.m607254200 |
| Popis: | Truncated hemoglobins (trHbs) constitute a distinct lineage in the globin superfamily, distantly related in size and fold to myoglobin and monomeric hemoglobins. Their phylogenetic analyses revealed that three groups (I, II, and III) compose the trHb family. Group I and II trHbs adopt a simplified globin fold, essentially composed of a 2-on-2 alpha-helical sandwich, wrapped around the heme group. So far no structural data have been reported for group III trHbs. Here we report the three-dimensional structure of the group III trHbP from the eubacterium Campylobacter jejuni. The 2.15-angstrom resolution crystal structure of C. jejuni trHbP (cyano-met form) shows that the 2-on-2 trHb fold is substantially conserved in the trHb group III, despite the absence of the Gly-based sequence motifs that were considered necessary for the attainment of the trHb specific fold. The heme crevice presents important structural modifications in the C-E region and in the FG helical hinge, with novel surface clefts at the proximal heme site. Contrary to what has been observed for group I and II trHbs, no protein matrix tunnel/cavity system is evident in C. jejuni trHbP. A gating movement of His(E7) side chain (found in two alternate conformations in the crystal structure) may be instrumental for ligand entry to the heme distal site. Sequence conservation allows extrapolating part of the structural results here reported to the whole trHb group III. |
| Databáze: | OpenAIRE |
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