PDBsum entry 1p69

Viral protein/receptor

PDB id: 1p69

Contents

Protein chains

185 a.a. *

124 a.a. *

* Residue conservation analysis

PDB id:

1p69

Name:

Viral protein/receptor

Title:

Structural basis for variation in adenovirus affinity for the cellular receptor car (p417s mutant)

Structure:

Fiber protein. Chain: a. Synonym: spike, protein iv. Engineered: yes. Mutation: yes. Coxsackievirus and adenovirus receptor. Chain: b. Synonym: hcar, cvb3-binding protein, coxsackievirus b-adenovirus receptor, hcvadr.

Source:

Human adenovirus a serotype 12. Hadv-12. Organism_taxid: 28282. Gene: l5. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008. Homo sapiens. Human. Organism_taxid: 9606.

Biol. unit:

Hexamer (from PQS)

Resolution:

3.10Å R-factor: 0.215 R-free: 0.256

Authors:

J.Howitt,M.C.Bewley,V.Graziano,J.M.Flanagan,P.Freimuth

Key ref:

J.Howitt et al. (2003). Structural basis for variation in adenovirus affinity for the cellular coxsackievirus and adenovirus receptor. J Biol Chem, 278, 26208-26215. PubMed id: 12716886 DOI: 10.1074/jbc.M301492200

Date:

29-Apr-03 Release date: 11-May-04

Protein chain

P36711  (SPIKE_ADE12) -  Fiber protein from Human adenovirus A serotype 12

Seq: 587 a.a.

Struc: 185 a.a.*

Protein chain

P78310  (CXAR_HUMAN) -  Coxsackievirus and adenovirus receptor from Homo sapiens

Seq: 365 a.a.

Struc: 124 a.a.*

* PDB and UniProt seqs differ at 2 residue positions (black crosses)

DOI no: 10.1074/jbc.M301492200

J Biol Chem 278:26208-26215 (2003)

PubMed id: 12716886

Structural basis for variation in adenovirus affinity for the cellular coxsackievirus and adenovirus receptor.

J.Howitt, M.C.Bewley, V.Graziano, J.M.Flanagan, P.Freimuth.

ABSTRACT

The majority of adenovirus serotypes can bind to the coxsackievirus and adenovirus receptor (CAR) on human cells despite only limited conservation of the amino acid residues that comprise the receptor-binding sites of these viruses. Using a fluorescence anisotropy-based assay, we determined that the recombinant knob domain of the fiber protein from adenovirus serotype (Ad) 2 binds the soluble, N-terminal domain (domain 1 (D1)) of CAR with 8-fold greater affinity than does the recombinant knob domain from Ad12. Homology modeling predicted that the increased affinity of Ad2 knob for CAR D1 could result from additional contacts within the binding interface contributed by two residues, Ser408 and Tyr477, which are not conserved in the Ad12 knob. Consistent with this structural model, substitution of serine and tyrosine for the corresponding residues in the Ad12 knob (P417S and S489Y) increased the binding affinity by 4- and 8-fold, respectively, whereas the double mutation increased binding affinity 10-fold. X-ray structure analysis of Ad12 knob mutants P417S and S489Y indicated that both substituted residues potentially could form additional hydrogen bonds across the knob-CAR interface. Structural changes resulting from these mutations were highly localized, implying that the high tolerance for surface variation conferred by the stable knob scaffold can minimize the impact of antigenic drift on binding specificity and affinity during evolution of virus serotypes. Our results suggest that the interaction of knob domains from different adenovirus serotypes with CAR D1 can be accurately modeled using the Ad12 knob-CAR D1 crystal structure as a template.

Selected figure(s)

Figure 3.
FIG. 3. Homology model of Ad2 knob bound to CAR D1. The x-ray structure of Ad2 knob was overlaid onto Ad12 knob in the x-ray structure of the Ad12 knob-CAR D1 complex. For simplicity, only one monomer of the knob trimer is shown. The surface of CAR D1 (space-filling model on left) is colored blue. Superimposed ribbon structures of Ad2 knob and Ad12 knob are colored cyan and green, respectively. Side chain residues of Ad12 knob contacting CAR D1 are shown in gray except for side chains of Ser489 and Pro417, which are shown in red. Ad2 knob Ser408 and Tyr477 side chains are colored yellow.

Figure 5.
FIG. 5. Comparison of crystal structures of wild type Ad12 knob-CAR D1 and Ad12 knob P417S-CAR D1. a, stereo figure showing part of the wild type Ad12 knob-CAR D1 interface including CAR D1 residues I55-E56-W57 (cyan) and Ad12 knob residues P416-P417-P418 (yellow); no hydrogen bonds are formed at this interface. b, stereo figure of same view of the interface between Ad12 knob mutant P417S (blue) and CAR D1 (red); note the novel hydrogen bond formed between Ser417 of knob and Glu56 of CAR D1.

The above figures are reprinted by permission from the ASBMB: J Biol Chem (2003, 278, 26208-26215) copyright 2003.

Figures were selected by an automated process.