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From Proteopedia
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
Structural highlights
FunctionRNH_ECOLI Endonuclease that specifically degrades the RNA of RNA-DNA hybrids. RNase H participates in DNA replication; it helps to specify the origin of genomic replication by suppressing initiation at origins other than the oriC locus; along with the 5'-3' exonuclease of pol1, it removes RNA primers from the Okazaki fragments of lagging strand synthesis; and it defines the origin of replication for ColE1-type plasmids by specific cleavage of an RNA preprimer.[HAMAP-Rule:MF_00042]RNH_THET8 Endonuclease that specifically degrades the RNA of RNA-DNA hybrids. Evolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedTo 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. Contributions of folding cores to the thermostabilities of two ribonucleases H.,Robic S, Berger JM, Marqusee S Protein Sci. 2002 Feb;11(2):381-9. PMID:11790848[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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