DNA polymerase family X: function, structure, and cellular roles.

Abstract:

The X family of DNA polymerases in eukaryotic cells consists of terminal transferase and DNA polymerases beta, lambda, and mu. These enzymes have similar structural portraits, yet different biochemical properties, especially in their interactions with DNA. None of these enzymes possesses a proofreading subdomain, and their intrinsic fidelity of DNA synthesis is much lower than that of a polymerase that functions in cellular DNA replication. In this review, we discuss the similarities and differences of three members of Family X: polymerases beta, lambda, and mu. We focus on biochemical mechanisms, structural variation, fidelity and lesion bypass mechanisms, and cellular roles. Remarkably, although these enzymes have similar three-dimensional structures, their biochemical properties and cellular functions differ in important ways that impact cellular function.

Polymerases:

Topics:

Historical Protein Properties (MW, pI, ...), Health/Disease, Kinetic Parameters, Nucleotide Analogs / Template Lesions, Structure and Structure/Function, Fidelity, Accessory Proteins/Complexes, Nucleotide Incorporation, Exonuclease Activity, Terminal Transferase, Source / Purification

Status:

new topics/pols set partial results complete validated

Results:

Polymerase Reference Property Result Context
Human Pol beta Yamtich J2010 Molecular Weight 39kD
Human Pol beta Yamtich J2010 3-5' Exonuclease (proofreading) No
Human Pol beta Yamtich J2010 5-3' Exonuclease No
Human Pol beta Yamtich J2010 Template lesions Bypasses Reaction: Nucleotide incorporation; Substrate: dCTP; DNA lesion: 8-oxo-dG
Human Pol beta Yamtich J2010 Template lesions Bypasses Reaction: Nucleotide incorporation
Human Pol beta Yamtich J2010 Template lesions Bypasses Reaction: Nucleotide incorporation
Human Pol beta Yamtich J2010 Amino Acids Contacting Primer Tyr271
Human Pol beta Yamtich J2010 Overall Error Rate 0.0005 errors/bp
Human Pol beta Yamtich J2010 Overall Error Rate 0.0024 errors/bp
Human Pol beta Yamtich J2010 Full length or truncated Full length
Human Pol beta Yamtich J2010 Amino Acids Contacting Template Arg283 and Tyr271
Human Pol beta Yamtich J2010 Other Important Residues Tyr271, Phe272, Asp276, and Asn279 = dNTP binding pocket; Tyr271 = important for both chemistry and dNTP binding, alters steady-state catalytic efficiency
Human Pol beta Yamtich J2010 Amino Acids Contacting NTP Phe272, Asp276 and Asn279
Human Pol beta Yamtich J2010 Strand Displacement Yes
Human Pol beta Yamtich J2010 Associated condition I260M and K289M - Cancer
Human Pol lamba Yamtich J2010 Terminal Transferase Yes
Human Pol lamba Yamtich J2010 Molecular Weight 68kD
Human Pol lamba Yamtich J2010 3-5' Exonuclease (proofreading) No
Human Pol lamba Yamtich J2010 5-3' Exonuclease No
Human Pol lamba Yamtich J2010 Template lesions Bypasses Reaction: Nucleotide incorporation; DNA lesion: 8-oxo-dG
Human Pol lamba Yamtich J2010 Full length or truncated Full length
Human Pol lamba Yamtich J2010 Vmax 2.1 /second Reaction: Nucleotide incorporation; Substrate: dNTPs
Human Pol lamba Yamtich J2010 Other accessory protein(s) PCNA, CDK2/CyclinA
Human Pol lamba Yamtich J2010 Gap Filling Yes
Human Pol mu Yamtich J2010 Terminal Transferase Yes
Human Pol mu Yamtich J2010 Molecular Weight 55kD
Human Pol mu Yamtich J2010 3-5' Exonuclease (proofreading) No
Human Pol mu Yamtich J2010 5-3' Exonuclease No
Human Pol mu Yamtich J2010 Template lesions Bypasses Reaction: Nucleotide incorporation; DNA lesion: 8-oxo-dG
Human Pol mu Yamtich J2010 Template lesions Bypasses Reaction: Nucleotide incorporation; DNA lesion: Apurinic/Apyrimidinic (AP) site
Human Pol mu Yamtich J2010 Full length or truncated Full length
Human Pol mu Yamtich J2010 Vmax 0.076 /second Reaction: Nucleotide incorporation; Substrate: dNTPs
Human Pol mu Yamtich J2010 Gap Filling Yes

Entry validated by:

Log in to edit reference All References

Using Polbase tables:

Sorting:

Tables may be sorted by clicking on any of the column titles. A second click reverses the sort order. <Ctrl> + click on the column titles to sort by more than one column (e.g. family then name).

Filtering:

It is also possible to filter the table by typing into the search box above the table. This will instantly hide lines from the table that do not contain your search text.