Protein Family Models

This is a highly divergent 3' exoribonuclease family. The proteins constitute a typical RNase fold, where the active site residues form a magnesium catalytic centre. The protein of the solved structure readily cleaves 3' overhangs in a time-dependent manner. It is similar to DEDD-type RNases and is an unusual ATP-binding protein that binds ATP and dATP. It forms a dimer in solution and both protomers in the asymmetric unit bind a magnesium ion through Asp-6 in SwissProt:P9WJ73 [1]. Proteins containing this domain also include 3'-5' exonuclease dexA from bacteriophage T4. It may play a role in the final step of host DNA degradation, by scavenging DNA into mononucleotides [2,3]. [1]. 24311791. Mycobacterium tuberculosis Rv2179c protein establishes a new exoribonuclease family with broad phylogenetic distribution. Abendroth J, Ollodart A, Andrews ES, Myler PJ, Staker BL, Edwards TE, Arcus VL, Grundner C;. J Biol Chem. 2014;289:2139-2147. [2]. 10581261. Role of exonucleolytic degradation in group I intron homing in phage T4. Huang YJ, Parker MM, Belfort M;. Genetics. 1999;153:1501-1512. [3]. 3056918. Effect of DNA sequence and structure on nuclease activity of the DexA protein of bacteriophage T4. Gruber H, Kern G, Gauss P, Gold L;. J Bacteriol. 1988;170:5830-5836. (from Pfam)

Date:

2024-10-16

Date:

2024-08-14

This family includes a variety of exonuclease proteins, such as ribonuclease T and the epsilon subunit of DNA polymerase III.; [1]. 8506149. RNase T shares conserved sequence motifs with DNA proofreading exonucleases. Koonin EV, Deutscher MP;. Nucleic Acids Res 1993;21:2521-2522. (from Pfam)

Date:

2024-10-16

3'-5' exonuclease similar to DNA polymerase III subunit epsilon and exodeoxyribonuclease 10

Date:

2017-02-03

Date:

2020-10-26

All proteins in this family for which functions are known are components of the DNA polymerase III complex (epsilon subunit). There is, however, an outgroup that includes paralogs in some gamma-proteobacteria and the n-terminal region of DinG from some low GC gram positive bacteria. This family is based on the phylogenomic analysis of JA Eisen (1999, Ph.D. Thesis, Stanford University).

Date:

2024-05-14