Crystal Structure of the Moloney Murine Leukemia Virus RNase H Domain.
Lim, D., Gregorio, G.G., Bingman, C.A., Martinez-Hackert, E., Hendrickson, W.A., Goff, S.P.(2006) J Virol 80: 8379-8389
- PubMed: 16912289 
- DOI: https://doi.org/10.1128/JVI.00750-06
- Primary Citation of Related Structures:  
2HB5 - PubMed Abstract: 
A crystallographic study of the Moloney murine leukemia virus (Mo-MLV) RNase H domain was performed to provide information about its structure and mechanism of action. These efforts resulted in the crystallization of a mutant Mo-MLV RNase H lacking the putative helix C (DeltaC). The 1.6-Angstroms resolution structure resembles the known structures of the human immunodeficiency virus type 1 (HIV-1) and Escherichia coli RNase H. The structure revealed the coordination of a magnesium ion within the catalytic core comprised of the highly conserved acidic residues D524, E562, and D583. Surface charge mapping of the Mo-MLV structure revealed a high density of basic charges on one side of the enzyme. Using a model of the Mo-MLV structure superimposed upon a structure of HIV-1 reverse transcriptase bound to an RNA/DNA hybrid substrate, Mo-MLV RNase H secondary structures and individual amino acids were examined for their potential roles in binding substrate. Identified regions included Mo-MLV RNase H beta1-beta2, alphaA, and alphaB and residues from alphaB to alphaD and its following loop. Most of the identified substrate-binding residues corresponded with residues directly binding nucleotides in an RNase H from Bacillus halodurans as observed in a cocrystal structure with RNA/DNA. Finally, superimposition of RNases H of Mo-MLV, E. coli, and HIV-1 revealed that a loop of the HIV-1 connection domain resides within the same region of the Mo-MLV and E. coli C-helix. The HIV-1 connection domain may serve to recognize and bind the RNA/DNA substrate major groove.
Organizational Affiliation: 
Integrated Program in Cellular, Molecular and Biophysical Studies, College of Physicians and Surgeons, Columbia University, New York, New York 10032, USA.