Role of leucine zipper-like motifs in the oligomerization of Pseudomonas putida phasins.
Coiled-coils
Oligomerization
Phasins
Polyhydroxyalkanoates
Pseudomonas
Journal
Biochimica et biophysica acta. General subjects
ISSN: 1872-8006
Titre abrégé: Biochim Biophys Acta Gen Subj
Pays: Netherlands
ID NLM: 101731726
Informations de publication
Date de publication:
02 2019
02 2019
Historique:
received:
15
06
2018
revised:
05
11
2018
accepted:
07
11
2018
pubmed:
13
11
2018
medline:
1
10
2019
entrez:
13
11
2018
Statut:
ppublish
Résumé
Phasins are low molecular mass proteins that accumulate strongly in bacterial cells in response to the intracellular storage of polyhydroxyalkanoates (PHA). Although lacking catalytic activity, phasins are the major components of the surface of the PHA granules and could be potentially involved in the formation of a network-like protein layer surrounding the polyester inclusions. Structural models revealed phasins to possess coiled-coil regions that might be important in the establishment of protein-protein interactions. However, there is not experimental evidence of a coiled-coil mediated oligomerization in these proteins. Structure prediction analyses were used to characterize the coiled-coil motifs of phasins PhaF and PhaI -produced by the model bacterium Pseudomonas putida KT2440-. Their oligomerization was evaluated by biolayer interferometry and the in vivo two-hybrid (BACTH) system. The interaction ability of a series of coiled-coil mutated derivatives was also measured. The formation of PhaF and PhaI complexes was detected. A predicted short leucine zipper-like coiled-coil (ZIP), containing "ideal" residues located within the hydrophobic core, was shown responsible for the oligomers stability. The substitution of key residues (leucines or valines) in PhaI ZIP (ZIPI) for alanine reduced by four fold the oligomerization efficiency. These results indicate that coiled-coil motifs are essential for phasin interactions. Correct oligomerization requires the formation of a stable hydrophobic interface between both phasins. Our findings elucidate the oligomerization motif of PhaF and PhaI. This motif is present in most phasins from PHA-accumulating bacteria and offers a potentially important target for modulating the PHA granules stability.
Sections du résumé
BACKGROUND
Phasins are low molecular mass proteins that accumulate strongly in bacterial cells in response to the intracellular storage of polyhydroxyalkanoates (PHA). Although lacking catalytic activity, phasins are the major components of the surface of the PHA granules and could be potentially involved in the formation of a network-like protein layer surrounding the polyester inclusions. Structural models revealed phasins to possess coiled-coil regions that might be important in the establishment of protein-protein interactions. However, there is not experimental evidence of a coiled-coil mediated oligomerization in these proteins.
METHODS
Structure prediction analyses were used to characterize the coiled-coil motifs of phasins PhaF and PhaI -produced by the model bacterium Pseudomonas putida KT2440-. Their oligomerization was evaluated by biolayer interferometry and the in vivo two-hybrid (BACTH) system. The interaction ability of a series of coiled-coil mutated derivatives was also measured.
RESULTS
The formation of PhaF and PhaI complexes was detected. A predicted short leucine zipper-like coiled-coil (ZIP), containing "ideal" residues located within the hydrophobic core, was shown responsible for the oligomers stability. The substitution of key residues (leucines or valines) in PhaI ZIP (ZIPI) for alanine reduced by four fold the oligomerization efficiency.
CONCLUSIONS
These results indicate that coiled-coil motifs are essential for phasin interactions. Correct oligomerization requires the formation of a stable hydrophobic interface between both phasins.
GENERAL SIGNIFICANCE
Our findings elucidate the oligomerization motif of PhaF and PhaI. This motif is present in most phasins from PHA-accumulating bacteria and offers a potentially important target for modulating the PHA granules stability.
Identifiants
pubmed: 30419286
pii: S0304-4165(18)30350-7
doi: 10.1016/j.bbagen.2018.11.002
pii:
doi:
Substances chimiques
Bacterial Proteins
0
DNA-Binding Proteins
0
PHAP protein, Bacteria
0
Polyhydroxyalkanoates
0
Types de publication
Journal Article
Research Support, Non-U.S. Gov't
Langues
eng
Sous-ensembles de citation
IM
Pagination
362-370Informations de copyright
Copyright © 2018 Elsevier B.V. All rights reserved.