Protein Family Models

Date:

2024-08-14

Some Proteobacteria topoisomerase I contain two zinc-ribbon-like domains at the C-terminus that structurally homologous to Pfam:PF01396. However, this domain no longer bind zinc. Indeed, only one of the four cysteine residues remains [1]. [1]. 10873443. C-terminal domains of Escherichia coli topoisomerase I belong to. the zinc-ribbon superfamily.. Grishin NV;. J Mol Biol 2000;299:1165-1177. (from Pfam)

Date:

2024-08-14

This HMM identifies a region shared by DNA topoisomerases of different types, including ATP-independent (type I) topoisomerases such as TopA and TopB, and ATP-dependent reverse gyrases.

Date:

2024-08-14

This is a conserved region from DNA primase. This corresponds to the Toprim domain common to DnaG primases, topoisomerases, OLD family nucleases and RecR proteins [1]. Both DnaG motifs IV and V are present in the alignment, the DxD (V) motif may be involved in Mg2+ binding and mutations to the conserved glutamate (IV) completely abolish DnaG type primase activity [1]. DNA primase EC:2.7.7.6 is a nucleotidyltransferase it synthesises the oligoribonucleotide primers required for DNA replication on the lagging strand of the replication fork; it can also prime the leading stand and has been implicated in cell division [2]. This family also includes the atypical archaeal A subunit from type II DNA topoisomerases [4]. Type II DNA topoisomerases catalyse the relaxation of DNA supercoiling by causing transient double strand breaks. [1]. 9722641. Toprim--a conserved catalytic domain in type IA and II. topoisomerases, DnaG-type primases, OLD family nucleases and. RecR proteins.. Aravind L, Leipe DD, Koonin EV;. Nucleic Acids Res 1998;26:4205-4213.. [2]. 9224947. Cloning and analysis of the dnaG gene encoding Pseudomonas. putida DNA primase.. Szafranski P, Smith CL, Cantor CR;. Biochim Biophys Acta 1997;1352:243-248.. [3]. 8294018. The Haemophilus influenzae dnaG sequence and conserved bacterial. primase motifs.. Versalovic J, Lupski JR;. Gene 1993;136:281-286.. [4]. 9121560. An atypical topoisomerase II from Archaea with implications for. meiotic recombination.. Bergerat A, de Massy B, Gadelle D, Varoutas PC, Nicolas A,. Forterre P;. Nature 1997;386:414-417. (from Pfam)

Date:

2024-08-14

Date:

2024-08-14

DNA topoisomerase I is a type IA DNA topoisomerase that releases the supercoiling and torsional tension of DNA, which is introduced during DNA replication and transcription, by transiently cleaving and rejoining one strand of the DNA duplex

Date:

2022-08-18

This model describes DNA topoisomerase I among the members of bacteria. DNA topoisomerase I transiently cleaves one DNA strand and thus relaxes negatively supercoiled DNA during replication, transcription and recombination events.

Gene:

topA

Date:

2021-04-27