1JL2

Crystal structure of TCEO RNase H-a chimera combining the folding core from T. thermophilus RNase H and the remaining region of E. coli RNase H

Summary for 1JL2

• Entry DOI: 10.2210/pdb1jl2/pdb
• Descriptor: Chimera of Ribonuclease HI, Ribonuclease H (2 entities in total)
• Functional Keywords: mixed alpha-beta protein, hydrolase
• Biological source: Escherichia coli (strain K12); More
• Cellular location: Cytoplasm : P0A7Y4
• Total number of polymer chains: 4
• Total formula weight: 70403.83

Authors

Robic, S.,Berger, J.M.,Marqusee, S. (deposition date: 2001-07-13, release date: 2002-01-18, Last modification date: 2023-08-16)

Primary citation

Robic, S.,Berger, J.M.,Marqusee, S.
Contributions of folding cores to the thermostabilities of two ribonucleases H.
Protein Sci., 11:381-389, 2002

PubMed Abstract: To investigate the contribution of the folding cores to the thermodynamic stability of RNases H, we used rational design to create two chimeras composed of parts of a thermophilic and a mesophilic RNase H. Each chimera combines the folding core from one parent protein and the remaining parts of the other. Both chimeras form active, well-folded RNases H. Stability curves, based on CD-monitored chemical denaturations, show that the chimera with the thermophilic core is more stable, has a higher midpoint of thermal denaturation, and a lower change in heat capacity (DeltaCp) upon unfolding than the chimera with the mesophilic core. A possible explanation for the low DeltaCp of both the parent thermophilic RNase H and the chimera with the thermophilic core is the residual structure in the denatured state. On the basis of the studied parameters, the chimera with the thermophilic core resembles a true thermophilic protein. Our results suggest that the folding core plays an essential role in conferring thermodynamic parameters to RNases H.

PubMed: 11790848
DOI: 10.1110/ps.38602

Experimental method

X-RAY DIFFRACTION (1.76 Å)