Bacterial and archaeal globins - a revised perspective.
Biochim Biophys Acta
; 1834(9): 1789-800, 2013 Sep.
Article
em En
| MEDLINE
| ID: mdl-23541529
ABSTRACT
A bioinformatics survey of putative globins in over 2200 bacterial and some 140 archaeal genomes revealed that over half the bacterial and approximately one fifth of archaeal genomes contain genes encoding globins that were classified into three families the M (myoglobin-like), and S (sensor) families all exhibiting the canonical 3/3 myoglobin fold, and the T family (truncated myoglobin fold). Although the M family comprises 2 subfamilies, flavohemoglobins (FHbs) and single domain globins (SDgbs), the S family encompasses chimeric globin-coupled sensors (GCSs), single domain Pgbs (protoglobins) and SSDgbs (sensor single domain globins). The T family comprises three classes TrHb1s, TrHb2s and TrHb3s, characterized by the abbreviated 2/2 myoglobin fold. The Archaea contain only Pgbs, GCSs and TrHb1s. The smallest globin-bearing genomes are the streamlined genomes (~1.3Mbp) of the SAR11 clade of alphaproteobacteria and the slightly larger (ca. 1.7Mbp) genomes of Aquificae. The smallest genome with members of all three families is the 2.3Mbp genome of the extremophile Methylacidiphilum infernorum (Verrumicrobia). Of the 147 possible combinations of the eight globin subfamilies, only 83 are observed. Although binary combinations are infrequent and ternary combinations are rare, the FHb+TrHb2 combination is the most commonly observed. Of the possible functions of bacterial globins we discuss the two principal ones - nitric oxide detoxification via the NO dioxygenase or denitrosylase activities and the sensing of oxygen concentration in the environmental niche. In only few cases has a physiological role been demonstrated in vivo. This article is part of a Special Issue entitled Oxygen Binding and Sensing Proteins.
Palavras-chave
Adgb; Archaea; Bacteria; Cygb; FHb; GCS; GbE; GbX; GbY; HGT; Hb; Hemoglobin; LECA; Last Universal Eukaryote Common Ancestor; Mb; Ngb; Pgb; Prokaryote; SDgb; SSDgb; androglobin; cytoglobin; flavohaemoglobin; globin E; globin X; globin Y; globin-coupled sensor; haemoglobin; horizontal gene transfer; myoglobin; neuroglobin; protoglobin; sensor single domain 3/3 globin related to the N-terminal of GCSs.; single domain 3/3 globin related to the N-terminal of FHbs
Texto completo:
1
Bases de dados:
MEDLINE
Assunto principal:
Bactérias
/
Globinas
/
Genoma Bacteriano
/
Archaea
/
Evolução Molecular
/
Genoma Arqueal
Idioma:
En
Revista:
Biochim Biophys Acta
Ano de publicação:
2013
Tipo de documento:
Article
País de afiliação:
Estados Unidos