The Herbaspirillum seropedicae genome sequence encodes a truncated hemoglobin typical of group II (Hs-trHb1) members of this family. We show that His-tagged recombinant Hs-trHb1 is monomeric in solution, and its optical spectrum resembles those of previously reported globins. NMR analysis allowed us to assign heme substituents. All data suggest that Hs-trHb1 undergoes a transition from an aquomet form in the ferric state to a hexacoordinate low-spin form in the ferrous state. The close positions of Ser-E7, Lys-E10, Tyr-B10, and His-CD1 in the distal pocket place them as candidates for heme coordination and ligand regulation. Peroxide degradation kinetics suggests an easy access to the heme pocket, as the protein offered no protection against peroxide degradation when compared with free heme. The high solvent exposure of the heme may be due to the presence of a flexible loop in the access pocket, as suggested by a structural model obtained by using homologous globins as templates. The truncated hemoglobin described here has unique features among truncated hemoglobins and may function in the facilitation of O(2) transfer and scavenging, playing an important role in the nitrogen-fixation mechanism.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1007/s00775-008-0394-3 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Dual α-globin-truncated erythropoietin receptor knockin restores hemoglobin production in α-thalassemia-derived erythroid cells.
Cell Rep
January 2025
Department of Surgery, University of California, San Francisco, San Francisco, CA 94143, USA; Eli & Edythe Broad Center for Regeneration Medicine, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Bioengineering & Therapeutic Sciences, University of California, San Francisco, San Francisco, CA 94158, USA. Electronic address:
The most severe form of α-thalassemia results from loss of all four copies of α-globin. Postnatally, patients face challenges similar to β-thalassemia, including severe anemia and erythrotoxicity due to the imbalance of β-globin and α-globin chains. Despite progress in genome editing treatments for β-thalassemia, there is no analogous curative option for α-thalassemia.
View Article and Find Full Text PDFHigh-efficiency expression of alginate lyase in Pichia pastoris facilitated by Vitreoscilla hemoglobin.
Int J Biol Macromol
December 2024
College of Food Science and Engineering, Ocean University of China, No. 1299 Sansha Road, Qingdao 266003, China. Electronic address:
Vitreoscilla hemoglobin (VHb) can enhance the ability of recombinant strains to express heterologous proteins under low-oxygen conditions. However, its mechanism of action in the Pichia pastoris expression system remains unclear. In this study, three VHb construction strategies were designed to elucidate the mechanisms by which VHb promotes heterologous protein expression in P.
View Article and Find Full Text PDFSwitching engineered Vitreoscilla hemoglobin into carbene transferase for enantioselective SH insertion.
Int J Biol Macromol
October 2024
Key Laboratory of Molecular Enzymology and Engineering of Ministry of Education, School of Life Sciences, Jilin University, Changchun 130023, PR China. Electronic address:
An attractive strategy for efficiently forming CS bonds is through the use of diazo compounds SH insertion. However, achieving good enantioselective control in this reaction within a biocatalytic system has proven to be challenging. This study aimed to enhance the activity and enantioselectivity of to enable asymmetric SH insertion.
View Article and Find Full Text PDFHeme d formation in a Shewanella benthica hemoglobin.
J Inorg Biochem
October 2024
T.C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, MD 21218, USA. Electronic address:
In our continued investigations of microbial globins, we solved the structure of a truncated hemoglobin from Shewanella benthica, an obligate psychropiezophilic bacterium. The distal side of the heme active site is lined mostly with hydrophobic residues, with the exception of a tyrosine, Tyr34 (CD1) and a histidine, His24 (B13). We found that purified SbHbN, when crystallized in the ferric form with polyethylene glycol as precipitant, turned into a green color over weeks.
View Article and Find Full Text PDFKinetic and dynamical properties of truncated hemoglobins of the Antarctic bacterium Pseudoalteromonas haloplanktis TAC125.
Protein Sci
July 2024
Department of Mathematical, Physical and Computer Sciences, University of Parma, Parma, Italy.
Due to the low temperature, the Antarctic marine environment is challenging for protein functioning. Cold-adapted organisms have evolved proteins endowed with higher flexibility and lower stability in comparison to their thermophilic homologs, resulting in enhanced reaction rates at low temperatures. The Antarctic bacterium Pseudoalteromonas haloplanktis TAC125 (PhTAC125) genome is one of the few examples of coexistence of multiple hemoglobin genes encoding, among others, two constitutively transcribed 2/2 hemoglobins (2/2Hbs), also named truncated Hbs (TrHbs), belonging to the Group II (or O), annotated as PSHAa0030 and PSHAa2217.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!