1. Volume 27, Issue 6, Pages 900-911 (December 2007)
The Heterodimeric Assembly of the CD94-NKG2 Receptor Family and Implications for Human Leukocyte Antigen-E Recognition 
Lucy C. Sullivan, Craig S. Clements, Travis Beddoe, Darryl Johnson, Hilary L. Hoare, Jie Lin, Trevor Huyton, Emma J. Hopkins, Hugh H. Reid, Matthew C.J. Wilce, Juraj Kabat, Francisco Borrego, John E. Coligan, Jamie Rossjohn, Andrew G. Brooks 
Immunity 
Volume 27, Issue 6, Pages (December 2007)
DOI: /j.immuni
Copyright © 2007 Elsevier Inc. Terms and Conditions

2. Figure 1 NKG2A and the C-type Lectin Family
NKG2A has a C-type lectin fold as seen in NKG2D (Protein Data Bank ID code 1MPU), CD94 (1B6E), CD69 (1E8I), and Ly49A (1QO3). The β strands are shown in blue and purple, the α helices in red, and disulfide bonds are in yellow. The secondary structure elements are labeled according to the CD94 nomenclature (Boyington et al., 1999).
Immunity  , DOI: ( /j.immuni )
Copyright © 2007 Elsevier Inc. Terms and Conditions

3. Figure 2 The CD94-NKG2A Heterodimer
(A) Ribbon representation of the overall structure of the heterodimer with NKG2A shown in purple, CD94 in green, and the interchain disulfide in yellow.
(B) Surface representation of the dimer interface highlighting the extensive interactions between the two subunits. Residues forming hydrogen bonds are shown in cyan, salt bridge partners are shown in red and blue, the cysteines that form the interchain disulfide are colored yellow, and residues involved in hydrophobic contacts are colored green.
(C and D) The two sites of interaction are labeled and shown in detail in (C) site 1 and (D) site 2. In these views, NKG2A residues involved in contacts are colored red and the corresponding CD94 residues are shown in cyan.
Immunity  , DOI: ( /j.immuni )
Copyright © 2007 Elsevier Inc. Terms and Conditions

4. Figure 3
The NKG2x Family
(A) Sequence alignment of NKG2A with other NKG2 receptors and CD94. Sequence alignments of the stem (italics) and CTLD ectodomains of NKG2x and CD94, showing intrachain cysteines in purple. Residues conserved between NKG2A, -2B, -2C, -2E, and -2H are indicated by the dashes. Substitutions between NKG2A and -2C isoforms that could account for the difference in affinity for HLA-E are highlighted in yellow. Secondary structures for NKG2A, NKG2D, and CD94 are shown above the sequences, with cylinders representing α helices and arrows representing β sheets. Residues involved in homodimerization (NKG2D) or heterodimerization (NKG2A and CD94) are shown in cyan, with interchain cysteines colored in red. Asterisks indicate putative HLA-E binding sites on CD94 and NKG2A.
(B) Ribbon representation of CD94-NKG2A heterodimer with the residues that differ between NKG2A and NKG2C shown in yellow and the interchain disulfide bond shown in red.
Immunity  , DOI: ( /j.immuni )
Copyright © 2007 Elsevier Inc. Terms and Conditions

5. Figure 4 Recognition of HLA-E by CD94-NKG2A
(A and B) Individual HLA-E (A) and CD94-NKG2A (B) residues were mutated, and the affinity of the interaction between the proteins was measured by surface plasmon resonance. Residues that had a major influence on binding when mutated are shown in red, residues with a minor influence are in yellow, and residues that did not alter affinity for binding when mutated are shown in blue. The positioning of the residues that had the largest effect on binding affinity suggests a diagonal docking mode of CD94-NKG2A onto HLA-E (black line). CD94 and NKG2A subunits are colored light green and light blue, respectively.
(C) Model of CD94-NKG2A recognition of HLA-E. CD94-NKG2A docking on HLA-E-VMAPRTLFL was modeled on the NKG2D-MIC-A structure (1HYR). A surface representation of CD94-NKG2A is shown in purple (NKG2A) and green (CD94), with the α helices of HLA-E in red and the VMAPRTLFL peptide in white. Residues that differ between NKG2A and NKG2C are colored yellow. CD94-NKG2A binding hotspots on HLA-E, as identified by mutagenesis, are shown as red spheres.
Immunity  , DOI: ( /j.immuni )
Copyright © 2007 Elsevier Inc. Terms and Conditions