Click on the linked example titles to view rotatable colored molecules in Protein Explorer, or click on the static figures to see them in greater detail.

Example 1: MHC Class I Heavy Chain (H-2Kb, PDB ID 2VAA chain A). 
Complexed With Beta-2 Microglobulin (Chain B) and Vesicular Stomatitis Virus Nucleoprotein (fragment 52-59, chain P). 

Here, both variability and conservation reflect function. Functional variability is seen in the peptide-binding groove (Fig. MHC_1, accomodating chain P). Allelic diversity in the population, concentrated in the inner surface of the groove, enables the population to present the maximal range of foreign (e.g. viral) peptides to T lymphocytes, for defensive immune responses. Conserved patches suggest functions, some of which may not yet be identified. Gln226 is known to be important in binding the CD8 coreceptor of the T cell (Kern et al.). Conservation is also evident in the interface binding chain B (Fig. MHC_2). Fig. MHC_3 shows a general view of the Protein explorer graphic page.
More on MHC structure is at the Lehninger and Martz sites. 
 

Fig. MHC_1	Fig. MHC_2	Fig. MHC_3

Example 2: Potassium Channel (Kcsa, PDB ID 1bl8 chain A) 
Potassium Channel (Kcsa, chains: A, B, C, D) From Streptomyces Lividans 

The potassium channel is an integral membrane protein with sequence similarity to all known K+ channels, particularly in the pore region. In Fig. 1bl8_1, we can see a general view of the conservation pattern of one of the four identical subunits (chain A, all other subunits in strands, K+ atoms yellow), which shows that ConSurf clearly detects the conservation among the amino acids facing the pore region (critical K+ signature sequence aa). Fig. 1bl8_2, shows in greater detail the the contact between a K+ atom and the highly conserved G77, Y78 and G79 amino acids, which are known to be absolutely required for K+ selectivity. 
More on the the structure and function of the potassium channel at ( Doyle et al.) 
 

Fig. 1bl8_1	Fig. 1bl8_2