title: Insight into the phylogenetic relationship and structural features of vertebrate myoglobin family.
abstract: Myoglobin (Mb) is studied to clarify the structure-function relationships in protein science. In this work, we report the results of a comparative analysis of amino acid sequences from 298 vertebrate Mbs. Forty-one high conserved residues were identified and seven of them were invariants [E18, G25, F43, V68, L72, H93 (proximal histidine) and H97]. E18 is the only invariant amino acid residue located out of the heme-pocket and Xe-cavities playing a role in interaction between the A and E-helices. A comparative analysis of several parameters related to amino acid composition shows an increase of average mass, accessible surface area and volume per residue from Actinopterygii to Mammalia and Aves. This may be due to an increased number of bulky residues reducing the non-specific cavities volume and thus improving the oxygen flow between the heme site and the outside of the protein. Finally, the phylogenetic analyses of Mb in vertebrates are consistent with an evolution that runs with the diversification of the species, but in which several episodes of gene duplication and lost have occurred, less frequently in the ancestors of great taxons, cartilaginous fishes and non-avian reptiles, most frequently in ray-finned fishes and mammals, and very frequently in birds.
authors.affiliation: Department of Biochemistry and Molecular Biology and Physiology, Faculty of Sciences, University of Valladolid, E-47011 Valladolid, Spain.
authors.forename: José M
authors.initials: JM
authors.lastname: Ferreras
authors.affiliation: Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Second University of Naples, I-81100 Caserta, Italy.
authors.forename: Sara
authors.initials: S
authors.lastname: Ragucci
authors.affiliation: Department of Biochemistry and Molecular Biology and Physiology, Faculty of Sciences, University of Valladolid, E-47011 Valladolid, Spain.
authors.forename: Lucía
authors.initials: L
authors.lastname: Citores
authors.affiliation: Department of Biochemistry and Molecular Biology and Physiology, Faculty of Sciences, University of Valladolid, E-47011 Valladolid, Spain.
authors.forename: Rosario
authors.initials: R
authors.lastname: Iglesias
authors.affiliation: Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Second University of Naples, I-81100 Caserta, Italy.
authors.forename: Paolo V
authors.initials: PV
authors.lastname: Pedone
authors.affiliation: Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Second University of Naples, I-81100 Caserta, Italy. Electronic address: antimo.dimaro@unina2.it.
authors.forename: Antimo
authors.initials: A
authors.lastname: Di Maro
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D030161:Avian Proteins / Q000737:chemistry / Q000235:genetics; D016384:Consensus Sequence; D019143:Evolution, Molecular; D029941:Fish Proteins / Q000737:chemistry / Q000235:genetics; D009211:Myoglobin / Q000737:chemistry* / Q000235:genetics; D010802:Phylogeny; D011487:Protein Conformation; D030162:Reptilian Proteins / Q000737:chemistry / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D014714:Vertebrates
chemical_list: D030161:Avian Proteins; D029941:Fish Proteins; D009211:Myoglobin; D030162:Reptilian Proteins
keywords: Amino acid composition; Molecular evolution; Vertebrate myoglobins