An Overview of the Proofreading Functions in Bacteria and in Severe Acute Respiratory Syndrome-Coronaviruses
International Journal of Biochemistry Research & Review · pp. 33–62 · Published 6 Aug 2021
10.9734/ijbcrr/2021/v30i330258Abstract
Aim: To understand the structure-function relationship of the proofreading (PR) functions in eubacteria and viruses with special reference to Severe Acute Respiratory Syndrome-Coronaviruses (SARS-CoVs) and propose a plausible mechanism of action for PR exonucleases of SARS-CoVs. Study Design: Bioinformatics, biochemical, site-directed mutagenesis (SDM), X-ray crystallographic data were used to study the structure-function relationships of the PR exonucleases from bacteria and CoVs. Methodology: The protein sequences of the PR exonucleases of various DNA polymerases, and RNA polymerases of SARS, SARS-related and human CoVs (HCoVs) were obtained from PUBMED and SWISS-PROT databases. The advanced version of Clustal Omega was used for protein sequence analysis. Along with the conserved motifs identified by the bioinformatics analysis, the data already available by biochemical, SDM experiments and X-ray crystallographic analysis on these enzymes were used to arrive at the possible active amino acids in the PR exonucleases of these crucial enzymes. Results: A complete analysis of the active sites of the PR exonucleases from various bacteria and CoVs were done. The multiple sequence alignment (MSA) analysis showed many conserved amino acids, small and large peptide regions among them. Based on the conserved motifs, the PR exonucleases are found to fit broadly into two superfamilies, viz. DEDD and polymerase-histidinol phosphatase (PHP) superfamilies. The bacterial DNA polymerases I and II, RNase D, RNase T and ε-subunit of DNA polymerases III belong to the DEDD superfamily. The PR enzymes from SARS, SARS-related CoVs and other HCoVs also essentially belong to the DEDD superfamily. The DEDD superfamily either uses an invariant Tyr or a His as proton acceptor during catalysis. Depending on the proton acceptor, they are further classified into DEDHD and DEDYD subfamilies. RNase T, ε-subunit of DNA polymerases III and the SARS, SARS-related CoVs and other HCoVs belong to DEDHD subfamily. However, the SARS, SARS-related CoVs and other HCoVs showed additional zinc finger motifs (ZFMs) in their active sites. DNA polymerases I, II and RNase D belong to DEDYD subfamily. The bacterial DNA polymerases X, YcdX phosphoesterases and the co-editing exonuclease of DNA polymerases III belong to the PHP superfamily. Based on the MSA, X-ray crystallographic analyses and SDM experiments, the proposed active-site proton acceptor is Tyr/His in DEDDY/H subfamilies and His in PHP superfamily of PR exonucleases. Conclusions: Based on the similarities of active site amino acids/motifs, it may be concluded that the DEDD and PHP superfamilies of PR exonucleases should have evolved from a common ancestor but diverged very long ago. The biochemical properties of these enzymes, including the four conserved acidic amino acid residues in the catalytic core, suggest that the CoVs might have acquired the exonuclease function, possibly from a prokaryote. However, the presence of two zinc fingers in the PR active site of the SARS, SARS-related CoVs and other HCoVs sets their PR exonucleases apart from other homologues.
References (27)
- 1 DNA Topoisomerases: Structure, Function, and Mechanism [DOI]
- 2 Structural basis for the 3′‐5′ exonuclease activity of Escherichia coli DNA polymerase I: a two metal ion mechanism. [DOI]
- 3 Nidovirales: Evolving the largest RNA virus genome [DOI]
- 4 Discovery of an RNA virus 3′→5′ exoribonuclease that is critically involved in coronavirus RNA synthesis [DOI]
- 5 Structural basis and functional analysis of the SARS coronavirus nsp14–nsp10 complex [DOI]
- 6 Exoribonuclease superfamilies: structural analysis and phylogenetic distribution [DOI]
- 7 The Curious Case of the Nidovirus Exoribonuclease: Its Role in RNA Synthesis and Replication Fidelity [DOI]
- 8 The Footprint of Genome Architecture in the Largest Genome Expansion in RNA Viruses [DOI]
- 9 RNA Viruses: RNA Roles in Pathogenesis, Coreplication and Viral Load [DOI]
- 10 Characterizing Transcriptional Regulatory Sequences in Coronaviruses and Their Role in Recombination [DOI]
- 11 The 3′‐5′ exonuclease of DNA polymerase I of Escherichia coli: contribution of each amino acid at the active site to the reaction. [DOI]
- 12 Mutants in the Exo I motif of Escherichia coli dnaQ: defective proofreading and inviability due to error catastrophe. [DOI]
- 13 Structural Basis for Proofreading during Replication of the Escherichia coli Chromosome [DOI]
- 14 Structural Insight into Translesion Synthesis by DNA Pol II [DOI]
- 15 Distribution and roles of X-family DNA polymerases in eukaryotes [DOI]
- 16 A coproofreading Zn2+-dependent exonuclease within a bacterial replicase [DOI]
- 17 Editing of misaligned 3'-termini by an intrinsic 3'-5' exonuclease activity residing in the PHP domain of a family X DNA polymerase [DOI]
- 18 The DNA-polymerase-X family: controllers of DNA quality? [DOI]
- 19 Crystal Structure of RNase T, an Exoribonuclease Involved in tRNA Maturation and End Turnover [DOI]
- 20 Characterization of DNA polymerase X from Thermus thermophilus HB8 reveals the POLXc and PHP domains are both required for 3′–5′ exonuclease activity [DOI]
- 21 The PHP domain of PolX from Staphylococcus aureus aids high fidelity DNA synthesis through the removal of misincorporated deoxyribo-, ribo- and oxidized nucleotides [DOI]
- 22 Recent Advances in Biological Research Vol. 1 [DOI]
- 23 DNA polymerase I: from crystal structure to function via genetics [DOI]
- 24 Evidence favouring the hypothesis of a conserved 3′–5′ exonuclease active site in DNA-dependent DNA polymerases [DOI]
- 25 Analyses of the Spike Proteins of Severe Acute Respiratory Syndrome-Related Coronaviruses [DOI]
- 26 RNA Dependent RNA Polymerases of Severe Acute Respiratory Syndrome-Related Coronaviruses- An Insight into their Active Sites and Mechanism of Action [DOI]
- 27 Multiple sequence analysis of polygalacturonases and invertases and phase shift in conserved motifs
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