PDBsum entry 1psz

Immune system

PDB id: 1psz

Contents

Protein chain

286 a.a. *

Metals

_ZN

Waters ×225

* Residue conservation analysis

PDB id:

1psz

Name:

Immune system

Title:

Pneumococcal surface antigen psaa

Structure:

Protein (surface antigen psaa). Chain: a. Engineered: yes. Mutation: yes. Other_details: the expressed construct lacks the pro-lipoprotein recognition sequence lxxc

Source:

Streptococcus pneumoniae. Organism_taxid: 1313. Strain: d39 (serotype 2). Atcc: nctc7466. Collection: nctc7466. Cellular_location: extracellular. Expressed in: escherichia coli. Expression_system_taxid: 562.

Resolution:

2.00Å R-factor: 0.178 R-free: 0.236

Authors:

M.C.Lawrence,P.A.Pilling,V.C.Epa,A.M.Berry,A.D.Ogunniyi,J.C.Paton

Key ref:

M.C.Lawrence et al. (1998). The crystal structure of pneumococcal surface antigen PsaA reveals a metal-binding site and a novel structure for a putative ABC-type binding protein. Structure, 6, 1553-1561. PubMed id: 9862808 DOI: 10.1016/S0969-2126(98)00153-1

Date:

13-Oct-98 Release date: 19-Apr-00

Protein chain

P0A4G2  (MTSA_STRPN) -  Manganese ABC transporter substrate-binding lipoprotein PsaA from Streptococcus pneumoniae serotype 4 (strain ATCC BAA-334 / TIGR4)

Seq: 309 a.a.

Struc: 286 a.a.

DOI no: 10.1016/S0969-2126(98)00153-1

Structure 6:1553-1561 (1998)

PubMed id: 9862808

The crystal structure of pneumococcal surface antigen PsaA reveals a metal-binding site and a novel structure for a putative ABC-type binding protein.

M.C.Lawrence, P.A.Pilling, V.C.Epa, A.M.Berry, A.D.Ogunniyi, J.C.Paton.

ABSTRACT

Background:. The surface protein PsaA of the pathogenic bacterium Streptococcus pneumoniae plays an essential role in its virulence. PsaA is a putative ATP-binding cassette-type (ABC-type) binding protein involved in the uptake of Mn2+ and possibly Zn2+ and is considered to be both a potential drug target and and a candidate vaccine component. Results:. The structure of PsaA has been determined to 2.0 A resolution using X-ray crystallography and is the first structure obtained for an ABC-type binding protein from a Gram-positive organism. The protein consists of two (beta/alpha)4 domains linked together by a single helix. A metal-binding site is formed in the domain interface by the sidechains of His67, His139, Glu205 and Asp280 and is occupied in the structure. Conclusions:. The structural topology of PsaA is fundamentally different from that of other ABC-type binding proteins determined thus far in that PsaA lacks the characteristic 'hinge peptides' involved in conformational change upon solute uptake and release. In our structure, the metal-binding site is probably occupied by Zn2+. The site seems to be well conserved amongst related receptors from both Gram-positive and Gram-negative bacteria.

Selected figure(s)

Figure 1.
Figure 1. The overall fold of PsaA. (a) View down the twofold pseudosymmetry axis relating the domains. Within each domain, b strands are shown in cyan and a helices in brown; the domain-connecting helix is colored magenta. The connecting loops within the N-terminal domain are in yellow, whilst those in the C-terminal domain are colored green. The four metal-coordinating residues are shown in ball-and-stick representation, with carbon atoms colored gray, nitrogen atoms blue and oxygen atoms red. The Zn2+ is shown in orange. (b) Stereogram of a Ca trace of PsaA. The b strands are designated A-H and domain a helices a-h; the location of the Zn2+ (orange) is also shown. The N and C termini are shown as a blue and a red sphere, respectively, the observed N terminus being Lys24. Every twentieth Ca atom is highlighted as a black sphere and labeled. The view direction is approximately orthogonal to that of (a). Figures were generated using the programs MOLSCRIPT [39] and RASTER3D [40 and 41].

The above figure is reprinted by permission from Cell Press: Structure (1998, 6, 1553-1561) copyright 1998.

Figure was selected by an automated process.