Serine residues in the β/γ crystallin family which are conserved both in sequence and in their structural environment. A) Superimposed cartoon representation of 5 members of the family. Four serine sidechains each form hydrogen bonds to mainchain atoms in a β-hairpin, which are conserved across the family. For clarity, one serine is shown (in magenta) in B) [PDB: 1a5d] C) [PDB: 4gcr] D) [PDB: 2bb2] E) [PDB: 1prs] and F) [PDB: 1bd7]. The conservation of these sidechain-to-mainchain interactions implies that they have an important role in the mainchain architecture of these proteins. G) Shows selected regions of a multiple sequence alignment of the β/γ crystallins containing the four conserved and buried serine residues (highlighted by red stars). The local structural environment of each residue in the alignment is displayed using JOY annotation . Pictures of protein structures were produced using Pymol and clipping was used for improving figure clarity .