Probe into a multi-protein prokaryotic organelle using thermal scanning assay reveals distinct properties of the core and the shell.
Bacterial microcompartments
Globular proteins
Self-assembly
Shell proteins
Thermal shift assay
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:
10 2020
10 2020
Historique:
received:
07
02
2020
revised:
26
06
2020
accepted:
29
06
2020
pubmed:
8
7
2020
medline:
15
12
2020
entrez:
8
7
2020
Statut:
ppublish
Résumé
Bacterial microcompartments represent the only reported category of prokaryotic organelles that are capable of functioning as independent bioreactors. In this organelle, a biochemical pathway with all the enzyme machinery is encapsulated within an all protein shell. The shell proteins and the enzymes have distinct structural features. It is hypothesized that flat shell proteins align sideways to form extended sheets and, the globular enzymes fill up the central core of the organelle. Using differential scanning fluorimetry, we explored the structure and functional alteration of Pdu BMC, involving tertiary or quaternary structures. Our findings exhibit that these intact BMCs as a whole behave similar to a globular protein with a rich hydrophobic core, which is exposed upon thermal insult. The encapsulated enzymes itself have a strong hydrophobic core, which is in line with the hydrophobic-collapse model of protein folding. The shell proteins, on the other hand, do not have a strong hydrophobic core and show a significant portion of exposed hydrophobic patches. We show for the first time the thermal unfolding profile of the BMC domain proteins and the unique exposure of hydrophobic patches in them might be required for anchoring the enzymes leading to better packaging of the micro-compartments. These observations indicate that the genesis of these unique bacterial organelles is driven by the hydrophobic interactions between the shell and the enzymes. Insights from this work will aid in the genetic and biochemical engineering of thermostable efficient enzymatic biomaterials.
Sections du résumé
BACKGROUND
Bacterial microcompartments represent the only reported category of prokaryotic organelles that are capable of functioning as independent bioreactors. In this organelle, a biochemical pathway with all the enzyme machinery is encapsulated within an all protein shell. The shell proteins and the enzymes have distinct structural features. It is hypothesized that flat shell proteins align sideways to form extended sheets and, the globular enzymes fill up the central core of the organelle.
METHODS
Using differential scanning fluorimetry, we explored the structure and functional alteration of Pdu BMC, involving tertiary or quaternary structures.
RESULTS
Our findings exhibit that these intact BMCs as a whole behave similar to a globular protein with a rich hydrophobic core, which is exposed upon thermal insult. The encapsulated enzymes itself have a strong hydrophobic core, which is in line with the hydrophobic-collapse model of protein folding. The shell proteins, on the other hand, do not have a strong hydrophobic core and show a significant portion of exposed hydrophobic patches.
CONCLUSION
We show for the first time the thermal unfolding profile of the BMC domain proteins and the unique exposure of hydrophobic patches in them might be required for anchoring the enzymes leading to better packaging of the micro-compartments.
GENERAL SIGNIFICANCE
These observations indicate that the genesis of these unique bacterial organelles is driven by the hydrophobic interactions between the shell and the enzymes. Insights from this work will aid in the genetic and biochemical engineering of thermostable efficient enzymatic biomaterials.
Identifiants
pubmed: 32634534
pii: S0304-4165(20)30192-6
doi: 10.1016/j.bbagen.2020.129680
pii:
doi:
Substances chimiques
Bacterial Proteins
0
Types de publication
Journal Article
Research Support, Non-U.S. Gov't
Langues
eng
Sous-ensembles de citation
IM
Pagination
129680Informations de copyright
Copyright © 2020 Elsevier B.V. All rights reserved.
Déclaration de conflit d'intérêts
Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.