Solution structure of At3g28950 from Arabidopsis thaliana

We determined the solution structure of At3g28950 from A. thaliana, a homolog of At5g39720, whose structure we solved earlier. The secondary structure of the 165‐aa protein consists of a 5‐strand antiparallel β‐barrel domain flanked by two α‐helices and a 2‐strand β‐sheet; an additional free C‐terminal α‐helix extends into solution. Bioinformatic searches and analyses suggest that members of this growing set of structurally related proteins have been recruited to serve a wide variety of functions ranging from γ‐glutamyl cyclotransferase activity to participation in plant responses to chemical and biotic stimuli. Expression of a human homolog is elevated in bladder cancer tissues. Expression patterns for At3g28950 and its Arabidopsis paralogs suggest that each one evolved a different physiological role. The At3g28950 structure was solved as part of a structural genomics effort, and the results demonstrate how such a project can further understanding of genome evolution in addition to sequence–structure and structure–function relationships. Proteins 2008. © 2008 Wiley‐Liss, Inc.