title: The truncated hemoglobins in the Antarctic psychrophilic bacterium Pseudoalteromonas haloplanktis TAC125.
abstract: The genome sequence of the Antarctic Gram-negative marine eubacterium Pseudoalteromonas haloplanktis TAC125 is a potential source of useful data on proteins from a cold-adapted microorganism. Identifying the bases of protein adaptation to higher or lower temperatures is important to understand the relationship between structure/function and life history on the Earth. The P. haloplanktis TAC125 genome contains three genes in distinct positions on chromosome I, named PSHAa0030, PSHAa2217 and PSHAa0458. These genes encode three truncated hemoglobins. The amino-acid identity between the three hemoglobins is less than 25% suggesting that these proteins may have different function(s) in bacterial cellular metabolism. The hemoglobin encoded by the PSHAa0030 gene has been cloned, expressed in Escherichia coli, purified and structurally characterised. This truncated hemoglobin is monomeric; circular dichroism shows high temperature resistance. The optical spectra of oxygenated and CO forms are similar to those of other truncated hemoglobins. Phylogenetic analyses show that two truncated globins encoded by the PSHAa0030 and PSHAa2217 genes belong to group II, and the third one encoded by PSHAa0458 to group I.
authors.affiliation: Institute of Protein Biochemistry, CNR, Via Pietro Castellino 111, I-80131 Naples, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Giordano
authors.forename: Ermenegilda
authors.initials: E
authors.lastname: Parrilli
authors.forename: Agnes
authors.initials: A
authors.lastname: Dettaï
authors.forename: Roberta
authors.initials: R
authors.lastname: Russo
authors.forename: Giulia
authors.initials: G
authors.lastname: Barbiero
authors.forename: Gennaro
authors.initials: G
authors.lastname: Marino
authors.forename: Guillaume
authors.initials: G
authors.lastname: Lecointre
authors.forename: Guido
authors.initials: G
authors.lastname: di Prisco
authors.forename: Luisa
authors.initials: L
authors.lastname: Tutino
authors.forename: Cinzia
authors.initials: C
authors.lastname: Verde
mesh_terms: D000595:Amino Acid Sequence; D000864:Antarctic Regions; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D002942:Circular Dichroism; D004591:Electrophoresis, Polyacrylamide Gel; D006420:Hemeproteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D010802:Phylogeny; D031161:Pseudoalteromonas / Q000235:genetics*; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013056:Spectrophotometry, Ultraviolet; D013696:Temperature
chemical_list: D001426:Bacterial Proteins; D006420:Hemeproteins; D011994:Recombinant Proteins