Conformation of the Solute-Binding Protein AdcAII Influences Zinc Uptake in Streptococcus pneumoniae.

Župan, ML; Luo, Z; Ganio, K; Pederick, VG; Neville, SL; Deplazes, E; Kobe, B; McDevitt, CA

Conformation of the Solute-Binding Protein AdcAII Influences Zinc Uptake in Streptococcus pneumoniae.

Župan, ML Luo, Z Ganio, K Pederick, VG Neville, SL Deplazes, E

Kobe, B McDevitt, CA

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Publisher:: Frontiers Media SA
Publication Type:: Journal Article
Citation:: Front Cell Infect Microbiol, 2021, 11, pp. 729981
Issue Date:: 2021

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Field	Value	Language
dc.contributor.author	Župan, ML
dc.contributor.author	Luo, Z
dc.contributor.author	Ganio, K
dc.contributor.author	Pederick, VG
dc.contributor.author	Neville, SL
dc.contributor.author	Deplazes, E https://orcid.org/0000-0003-2052-5536
dc.contributor.author	Kobe, B
dc.contributor.author	McDevitt, CA
dc.date.accessioned	2022-01-12T07:10:08Z
dc.date.available	2021-07-27
dc.date.available	2022-01-12T07:10:08Z
dc.date.issued	2021
dc.identifier.citation	Front Cell Infect Microbiol, 2021, 11, pp. 729981
dc.identifier.issn	2235-2988
dc.identifier.issn	2235-2988
dc.identifier.uri	http://hdl.handle.net/10453/152998
dc.description.abstract	Streptococcus pneumoniae scavenges essential zinc ions from the host during colonization and infection. This is achieved by the ATP-binding cassette transporter, AdcCB, and two solute-binding proteins (SBPs), AdcA and AdcAII. It has been established that AdcAII serves a greater role during initial infection, but the molecular details of how the protein selectively acquires Zn(II) remain poorly understood. This can be attributed to the refractory nature of metal-free AdcAII to high-resolution structural determination techniques. Here, we overcome this issue by separately mutating the Zn(II)-coordinating residues and performing a combination of structural and biochemical analyses on the variant proteins. Structural analyses of Zn(II)-bound AdcAII variants revealed that specific regions within the protein underwent conformational changes via direct coupling to each of the metal-binding residues. Quantitative in vitro metal-binding assays combined with affinity determination and phenotypic growth assays revealed that each of the four Zn(II)-coordinating residues contributes to metal binding by AdcAII. Intriguingly, the phenotypic growth impact of the mutant adcAII alleles was, in general, independent of affinity, suggesting that the Zn(II)-bound conformation of the SBP is crucial for efficacious metal uptake. Collectively, these data highlight the intimate coupling of ligand affinity with protein conformational change in ligand-receptor proteins and provide a putative mechanism for AdcAII. These findings provide further mechanistic insight into the structural and functional diversity of SBPs that is broadly applicable to other prokaryotes.
dc.format	Electronic-eCollection
dc.language	eng
dc.publisher	Frontiers Media SA
dc.relation	http://purl.org/au-research/grants/nhmrc/1122582
dc.relation.ispartof	Front Cell Infect Microbiol
dc.relation.isbasedon	10.3389/fcimb.2021.729981
dc.rights	info:eu-repo/semantics/openAccess
dc.subject	0601 Biochemistry and Cell Biology, 0605 Microbiology
dc.subject.mesh	ATP-Binding Cassette Transporters
dc.subject.mesh	Bacterial Proteins
dc.subject.mesh	Biological Transport
dc.subject.mesh	Protein Binding
dc.subject.mesh	Protein Conformation
dc.subject.mesh	Streptococcus pneumoniae
dc.subject.mesh	Zinc
dc.subject.mesh	Streptococcus pneumoniae
dc.subject.mesh	Zinc
dc.subject.mesh	Bacterial Proteins
dc.subject.mesh	ATP-Binding Cassette Transporters
dc.subject.mesh	Protein Conformation
dc.subject.mesh	Protein Binding
dc.subject.mesh	Biological Transport
dc.title	Conformation of the Solute-Binding Protein AdcAII Influences Zinc Uptake in Streptococcus pneumoniae.
dc.type	Journal Article
utslib.citation.volume	11
utslib.location.activity	Switzerland
utslib.for	0601 Biochemistry and Cell Biology
utslib.for	0605 Microbiology
pubs.organisational-group	/University of Technology Sydney
pubs.organisational-group	/University of Technology Sydney/Faculty of Science
pubs.organisational-group	/University of Technology Sydney/Faculty of Science/School of Life Sciences
utslib.copyright.status	open_access	*
dc.date.updated	2022-01-12T07:10:03Z
pubs.publication-status	Published online
pubs.volume	11

Abstract:

Streptococcus pneumoniae scavenges essential zinc ions from the host during colonization and infection. This is achieved by the ATP-binding cassette transporter, AdcCB, and two solute-binding proteins (SBPs), AdcA and AdcAII. It has been established that AdcAII serves a greater role during initial infection, but the molecular details of how the protein selectively acquires Zn(II) remain poorly understood. This can be attributed to the refractory nature of metal-free AdcAII to high-resolution structural determination techniques. Here, we overcome this issue by separately mutating the Zn(II)-coordinating residues and performing a combination of structural and biochemical analyses on the variant proteins. Structural analyses of Zn(II)-bound AdcAII variants revealed that specific regions within the protein underwent conformational changes via direct coupling to each of the metal-binding residues. Quantitative in vitro metal-binding assays combined with affinity determination and phenotypic growth assays revealed that each of the four Zn(II)-coordinating residues contributes to metal binding by AdcAII. Intriguingly, the phenotypic growth impact of the mutant adcAII alleles was, in general, independent of affinity, suggesting that the Zn(II)-bound conformation of the SBP is crucial for efficacious metal uptake. Collectively, these data highlight the intimate coupling of ligand affinity with protein conformational change in ligand-receptor proteins and provide a putative mechanism for AdcAII. These findings provide further mechanistic insight into the structural and functional diversity of SBPs that is broadly applicable to other prokaryotes.

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http://hdl.handle.net/10453/152998