Folding studies of immunoglobulin-like beta-sandwich proteins suggest that they share a common folding pathway.
BACKGROUND
Are folding pathways conserved in protein families? To test this explicitly and ask to what extent structure specifies folding pathways requires comparison of proteins with a common fold. Our strategy is to choose members of a highly diverse protein family with no conservation of function and little or no sequence identity, but with structures that are essentially the same. The immunoglobulin-like fold is one of the most common structural families, and is subdivided into superfamilies with no detectable evolutionary or functional relationship.


RESULTS
We compared the folding of a number of immunoglobulin-like proteins that have a common structural core and found a strong correlation between folding rate and stability. The results suggest that the folding pathways of these immunoglobulin-like proteins share common features.


CONCLUSIONS
This study is the first to compare the folding of structurally related proteins that are members of different superfamilies. The most likely explanation for the results is that interactions that are important in defining the structure of immunoglobulin-like proteins are also used to guide folding.
Clarke
J
J
Department of Chemistry, Centre for Protein Engineering, University of Cambridge Lensfield Road, Cambridge, CB2 1EW, UK. jc162@cam.ac.uk.
Cota
E
E
Fowler
S B
SB
Hamill
S J
SJ
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D018801:CD2 Antigens / Q000737:chemistry; D015820:Cadherins / Q000737:chemistry; D029742:Caenorhabditis elegans Proteins; D002148:Calmodulin-Binding Proteins / Q000737:chemistry; D064211:Connectin; D005353:Fibronectins / Q000737:chemistry*; D007136:Immunoglobulins / Q000737:chemistry*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009124:Muscle Proteins / Q000737:chemistry; D017510:Protein Folding; D011494:Protein Kinases / Q000737:chemistry; D011506:Proteins / Q000737:chemistry*; D016415:Sequence Alignment; D019063:Tenascin / Q000737:chemistry
D018801:CD2 Antigens; D015820:Cadherins; D029742:Caenorhabditis elegans Proteins; D002148:Calmodulin-Binding Proteins; D064211:Connectin; D005353:Fibronectins; D007136:Immunoglobulins; D009124:Muscle Proteins; D011506:Proteins; D019063:Tenascin; C489233:unc-22 protein, C elegans; D011494:Protein Kinases