Cohesin-dockerin interaction in cellulosome assembly: a single Asp-to-Asn mutation disrupts high-affinity cohesin-dockerin binding.
The cohesive cellulosome complex is sustained by the high-affinity cohesin-dockerin interaction. In previous work, we demonstrated that a single Thr-to-Leu replacement in the Clostridium thermocellum dockerin component differentiates between non-recognition and high-affinity recognition by the interspecies rival cohesin from C. cellulolyticum. In this report, we show that a single Asp-to-Asn substitution on the cohesin counterpart also disrupts normal recognition of the dockerin. The Asp34 carboxyl group of the cohesin appears to play a central role in the resultant hydrogen-bonding network as an acceptor of two crucial hydrogen bonds from Ser45 of the dockerin domain. The results underscore the fragile nature of the intermolecular contact interactions that maintain this very high-affinity protein--protein interaction.
Department of Biotechnology and Food Engineering, Technion -- Israel Institute of Technology, Haifa, Israel.
Tal
T
Handelsman
Yoav
Y
Barak
David
D
Nakar
Adva
A
Mechaly
Raphael
R
Lamed
Yuval
Y
Shoham
Edward A
EA
Bayer
D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018797:Cell Cycle Proteins; D002868:Chromosomal Proteins, Non-Histone; D003013:Clostridium / Q000235:genetics* / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005656:Fungal Proteins; D007700:Kinetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D020125:Mutation, Missense / Q000235:genetics*; D009687:Nuclear Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D011487:Protein Conformation; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D000097722:Cohesins
D001426:Bacterial Proteins; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D002868:Chromosomal Proteins, Non-Histone; D005656:Fungal Proteins; D009687:Nuclear Proteins; D000097722:Cohesins