Cohesin-dockerin interactions within and between Clostridium josui and Clostridium thermocellum: binding selectivity between cognate dockerin and cohesin domains and species specificity.
The cellulosome components are assembled into the cellulosome complex by the interaction between one of the repeated cohesin domains of a scaffolding protein and the dockerin domain of an enzyme component. We prepared five recombinant cohesin polypeptides of the Clostridium thermocellum scaffolding protein CipA, two dockerin polypeptides of C. thermocellum Xyn11A and Xyn10C, four cohesin polypeptides of Clostridium josui CipA, and two dockerin polypeptides of C. josui Aga27A and Cel8A, and qualitatively and quantitatively examined the cohesin-dockerin interactions within C. thermocellum and C. josui, respectively, and the species specificity of the cohesin-dockerin interactions between these two bacteria. Surface plasmon resonance (SPR) analysis indicated that there was a certain selectivity, with a maximal 34-fold difference in the K(D) values, in the cohesin-dockerin interactions within a combination of C. josui, although this was not detected by qualitative analysis. Affinity blotting analysis suggested that there was at least one exception to the species specificity in the cohesin-dockerin interactions, although species specificity was generally conserved among the cohesin and dockerin polypeptides from C. thermocellum and C. josui, i.e. the dockerin polypeptides of C. thermocellum Xyn11A exceptionally bound to the cohesin polypeptides from C. josui CipA. SPR analysis confirmed this exceptional binding. We discuss the relationship between the species specificity of the cohesin-dockerin binding and the conserved amino acid residues in the dockerin domains.
Jindou
Sadanari
S
Faculty of Bioresources, Mie University, 1515 Kamihamacho, Tsu 514-8507, Japan.
Soda
Akane
A
Karita
Shuichi
S
Kajino
Tsutomu
T
Béguin
Pierre
P
Wu
J H David
JH
Inagaki
Minoru
M
Kimura
Tetsuya
T
Sakka
Kazuo
K
Ohmiya
Kunio
K
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism; D018797:Cell Cycle Proteins; D002480:Cellulase / Q000737:chemistry* / Q000378:metabolism; D002868:Chromosomal Proteins, Non-Histone; D003013:Clostridium / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000378:metabolism; D005656:Fungal Proteins; D007700:Kinetics; D008565:Membrane Proteins / Q000737:chemistry* / Q000378:metabolism; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000737:chemistry* / Q000378:metabolism; D010455:Peptides / Q000737:chemistry; D010957:Plasmids / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D013379:Substrate Specificity; D020349:Surface Plasmon Resonance; D013997:Time Factors; D000097722:Cohesins
D001426:Bacterial Proteins; D018797:Cell Cycle Proteins; D002480:Cellulase; D002868:Chromosomal Proteins, Non-Histone; D005656:Fungal Proteins; D008565:Membrane Proteins; D009687:Nuclear Proteins; D010455:Peptides; D011994:Recombinant Proteins; D000097722:Cohesins; C080369:CipA protein, Clostridium; C071223:endoglucanase Ss