SASDA35: SeZinT-SeZnuA complex (High-affinity zinc transporter periplasmic...

Basic information

• Entry: Database: SASBDB / ID: SASDA35

Sample

SeZinT-SeZnuA complex

• High-affinity zinc transporter periplasmic component (protein), ZinT, Salmonella enterica subsp. enterica serovar Nchanga
• Zinc/cadmium-binding protein (protein), SeZnuA, Salmonella enterica subsp. enterica serovar Enteritidis

• Function / homology: : / :
• Biological species: Salmonella enterica subsp. enterica serovar Nchanga (bacteria); Salmonella enterica subsp. enterica serovar Enteritidis (bacteria)
• Citation: Journal: Biochim Biophys Acta / Year: 2014; Title: The Salmonella enterica ZinT structure, zinc affinity and interaction with the high-affinity uptake protein ZnuA provide insight into the management of periplasmic zinc.; Authors: Andrea Ilari / Flaminia Alaleona / Giancarlo Tria / Patrizia Petrarca / Andrea Battistoni / Carlotta Zamparelli / Daniela Verzili / Mattia Falconi / Emilia Chiancone / ; Abstract: BACKGROUND: In Gram-negative bacteria the ZnuABC transporter ensures adequate zinc import in Zn(II)-poor environments, like those encountered by pathogens within the infected host. Recently, the metal-binding protein ZinT was suggested to operate as an accessory component of ZnuABC in periplasmic zinc recruitment. Since ZinT is known to form a ZinT-ZnuA complex in the presence of Zn(II) it was proposed to transfer Zn(II) to ZnuA. The present work was undertaken to test this claim.; METHODS: ZinT and its structural relationship with ZnuA have been characterized by multiple biophysical techniques (X-ray crystallography, SAXS, analytical ultracentrifugation, fluorescence spectroscopy).; RESULTS: The metal-free and metal-bound crystal structures of Salmonella enterica ZinT show one Zn(II) binding site and limited structural changes upon metal removal. Spectroscopic titrations with Zn(II) yield a KD value of 22±2nM for ZinT, while those with ZnuA point to one high affinity (KD<20nM) and one low affinity Zn(II) binding site (KD in the micromolar range). Sedimentation velocity experiments established that Zn(II)-bound ZinT interacts with ZnuA, whereas apo-ZinT does not. The model of the ZinT-ZnuA complex derived from small angle X-ray scattering experiments points to a disposition that favors metal transfer as the metal binding cavities of the two proteins face each other.; CONCLUSIONS: ZinT acts as a Zn(II)-buffering protein that delivers Zn(II) to ZnuA.; GENERAL SIGNIFICANCE: Knowledge of the ZinT-ZnuA relationship is crucial for understanding bacterial Zn(II) uptake.

Contact author

• Giancarlo Tria (EMBL-Hamburg, European Molecular Biology Laboratory (EMBL) - Hamburg outstation, Notkestraße 85, Geb. 25A, 22607 Hamburg, Deutschland, Germany)

Models

• Model #91: ; Type: mix / Radius of dummy atoms: 1.90 A / Chi-square value: 1.317904; Search similar-shape structures of this assembly by Omokage search (details)
• Model #92: ; Type: dummy / Radius of dummy atoms: 1.90 A; Search similar-shape structures of this assembly by Omokage search (details)

Sample

• Sample: Name: SeZinT-SeZnuA complex / Sample MW: 56.49 kDa / Specimen concentration: 0.17-5.00 / Entity id: 75 / 76
• Buffer: Name: 50 mM HEPES 50 mM KCl / Concentration: 50.00 mM / PK: 7 / pH: 7.5 / Comment: 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid / Composition: KCl 50.000 mM

Entity #75

Name: ZinT / Type: protein
Description: High-affinity zinc transporter periplasmic component
Formula weight: 33.25 / Num. of mol.: 1 / Source: Salmonella enterica subsp. enterica serovar Nchanga / References: UniProt: V2JZU2
Sequence:

FAALSAALWG SATQAADAAV VASLKPLGFI ASAIADGVTD TQVLLPDGAS EHDYSLRPSD VKRLQGADLV VWVGPEMEAF MEKSVRNIPD NKQVTIAQLA DVKPLLMKGA DDDEDEHAHT GADEEKGDVH HHHGEYNMHL WLSPEIARAT AVAIHEKLVE LMPQSRAKLD ANLKDFEAQL AATDKQVGNE LAPLKGKGYF VFHDAYGYYE KHYGLTPLGH FTVNPEIQPG AQRLHEIRTQ LVEQKATCVF AEPQFRPAVV EAVARGTSVR MGTLDPLGTN IKLGKTSYSA FLSQLANQYA SCLKGD

Entity #76

Name: SeZnuA / Type: protein / Description: Zinc/cadmium-binding protein / Formula weight: 23.24 / Num. of mol.: 1
Source: Salmonella enterica subsp. enterica serovar Enteritidis
References: UniProt: L6R5I5
Sequence:

MLLVNSPAFA HGHHAHGAPM TEVEQKAAAG VFDDANVRDR ALTDWDGMWQ SVYPYLVSGE LDPVFRQKAK KDPEKTFEDI KAYYRKGYVT NVETIGIENG VIEFHRDNNV ASCKYNYAGY KILTYASGKK GVRYLFECKD ANSKAPKYVQ FSDHIIAPRK SAHFHIFMGN TSQQALLQEM ENWPTYYPYQ LKANEVVDEM LHH

Experimental information

• Beam: Instrument name: ESRF BM29 / City: Grenoble / 国: France / Type of source: X-ray synchrotron / Wavelength: 0.93 Å / Dist. spec. to detc.: 2.43 mm
• Detector: Name: Pilatus 1M

Scan

Title: SeZinT-SeZnuA / Measurement date: May 9, 2013 / Storage temperature: 4 °C / Cell temperature: 4 °C / Exposure time: 1 sec. / Number of frames: 10 / Unit: 1/nm /

	Min	Max
Q	0.0499	3.6005

Distance distribution function P(R)

Sofotware P(R): GNOM 4.6 / Number of points: 456 /

	Min	Max
Q	0.2409	2.216
P(R) point	45	500
R	0	8.5

Result

Type of curve: extrapolated / Standard: BSA /

	Experimental	Porod
MW	43 kDa	-
Volume	-	55 nm3

	P(R)	Guinier
Forward scattering, I0	45.55	45.524
Radius of gyration, Rg	2.5 nm	2.5 nm

	Min	Max
D	-	8.5
Guinier point	45	105