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Structure and metal-binding properties of PA4063, a novel player in peripiasmic zinc tratficking by Pseudomonas aeruginosa
- Source :
- 'Acta Crystallographica D ', vol: 77, pages: 1401-1410 (2021), Acta Crystallographica. Section D, Structural Biology
- Publication Year :
- 2021
-
Abstract
- The structural and zinc-binding properties of PA4063, one of the periplasmic proteins expressed by Pseudomonas aeruginosa under zinc-deficient conditions, are presented. PA4063 has a noncanonical ferredoxin-like fold. Two zinc-binding sites with micromolar affinity are exposed and are located on the same face of the structure. Two histidine-rich loops, which are disordered in the apoprotein, contribute to zinc coordination in one of the sites. These findings strongly suggest a role for PA4063 in zinc trafficking, possibly acting as a metal chaperone or as a regulator of a transport system.<br />The capability to obtain essential nutrients in hostile environments is a critical skill for pathogens. Under zinc-deficient conditions, Pseudomonas aeruginosa expresses a pool of metal homeostasis control systems that is complex compared with other Gram-negative bacteria and has only been partially characterized. Here, the structure and zinc-binding properties of the protein PA4063, the first component of the PA4063–PA4066 operon, are described. PA4063 has no homologs in other organisms and is characterized by the presence of two histidine-rich sequences. ITC titration detected two zinc-binding sites with micromolar affinity. Crystallographic characterization, performed both with and without zinc, revealed an α/β-sandwich structure that can be classified as a noncanonical ferredoxin-like fold since it differs in size and topology. The histidine-rich stretches located at the N-terminus and between β3 and β4 are disordered in the apo structure, but a few residues become structured in the presence of zinc, contributing to coordination in one of the two sites. The ability to bind two zinc ions at relatively low affinity, the absence of catalytic cavities and the presence of two histidine-rich loops are properties and structural features which suggest that PA4063 might play a role as a periplasmic zinc chaperone or as a concentration sensor useful for optimizing the response of the pathogen to zinc deficiency.
- Subjects :
- Models, Molecular
Operon
Protein Conformation
chemistry.chemical_element
Zinc
medicine.disease_cause
Crystallography, X-Ray
Ferredoxin-like fold
PA4063
periplasmic zinc trafficking
Pseudomonas aeruginosa
amino acid sequence
binding sites
crystallography, X-ray
humans
models, molecular
protein binding
protein conformation
Pseudomonas infections
zinc
X-ray
Metal
models
Structural Biology
medicine
Humans
Pseudomonas Infections
molecular
Amino Acid Sequence
Settore BIO/10
crystallography
ferredoxin-like fold
Binding Sites
biology
Chemistry
Periplasmic space
biology.organism_classification
medicine.disease
Research Papers
Biochemistry
Chaperone (protein)
visual_art
biology.protein
visual_art.visual_art_medium
Zinc deficiency
Bacteria
Protein Binding
Subjects
Details
- Language :
- English
- ISSN :
- 20597983
- Volume :
- 77
- Database :
- OpenAIRE
- Journal :
- Acta Crystallographica D
- Accession number :
- edsair.doi.dedup.....35ec44e09e32180363a4c5b77e6d3832