topA
168
DNA topoisomerase I
locus
BSU_16120
Molecular weight
78.89 kDa
pI
9.02
function
relaxation of negatively supercoiled DNA behind RNA polymerase
product
DNA topoisomerase I
essential
quasi
ec
5.99.1.2
synonyms
topA, topI
Outlinks
Genomic Context
Categories containing this gene/protein
List of homologs in different organisms, belongs to COG0551 (Galperin et al., 2021)
This gene is a member of the following regulons
Gene
Coordinates
1,683,661 1,685,736
Phenotypes of a mutant
the mutant tends to acquire suppressor mutations that result in improved growth [Pubmed|28189581]
essential [Pubmed|25092907]
non-essential according to [Pubmed|28189581], but only one resistance cassette was possible
quasi-essential, deletion of [gene|41199C76DF8CA804B7B8878D61228B9542A96AE4|topA] results in the immediate acquisition of suppressor mutations that result in overexpression of [protein|1901C52DCB24B3D53150F6926C14907AC1B75293|parE]-[protein|9075DD0CC0B8554F0379732453665F43C70EFC26|parC] [pubmed|30957856]
The protein
Catalyzed reaction/ biological activity
relaxation of negatively supercoiled DNA
ATP-independent breakage of single-stranded DNA, followed by passage and rejoining (according to UniProt)
Protein family
Type IA topoisomerase family (together with [protein|7D5327BD1DD5FD5F90B2C849589923AA3D8B20EF|topB])(according to UniProt)
[wiki|Domains]
N-terminal [wiki|TOPRIM domain] (aa 3-114) [Pubmed|9722641]
Structure
[PDB|4RUL] (from ''E. coli'', 40% identity) [Pubmed|26490962]
[AF|P39814]
Paralogous protein(s)
[protein|7D5327BD1DD5FD5F90B2C849589923AA3D8B20EF|topB]
Expression and Regulation
Operons
genes
[gene|D72175937B3956C2BC500FC00CEC8EC57A0A76A8|sucC]-[gene|5900CAC1CE367F33B267673A7FC210A3A269B30E|sucD]-[gene|FC53216F600994C862F0C0D017C3FA28EB75DCB6|dprA]-[gene|41199C76DF8CA804B7B8878D61228B9542A96AE4|topA]
description
[Pubmed|22383849]
regulation
repressed by glucose (2.4-fold) ([protein|E39AFEB7B7F28969A35C4B51CC6E7819F71C79D9|ccpA]) [Pubmed|12850135]
expression is heterogeneous [pubmed|29809139]
regulatory mechanism
[protein|E39AFEB7B7F28969A35C4B51CC6E7819F71C79D9|ccpA]: repression, [Pubmed|12850135], in [regulon|protein:E39AFEB7B7F28969A35C4B51CC6E7819F71C79D9|ccpA regulon]
genes
[gene|41199C76DF8CA804B7B8878D61228B9542A96AE4|topA]
description
[Pubmed|22383849]
additional information
[wiki|translation] is likely to require [protein|search|Efp] due to the presence of several consecutive proline residues [PubMed|23239624,23239623]
Biological materials
Mutant
BKK16120 (Δ[gene|41199C76DF8CA804B7B8878D61228B9542A96AE4|topA]::kan trpC2) available at [http://bgsc.org/getdetail.php?bgscid=BKK16120 BGSC], [Pubmed|28189581], upstream reverse: _UP1_CATTTTCATCCCCCTCAAGA, downstream forward: _UP4_TAGCGGTGAGCAGGGTCTTG
GP1963 (Δ[gene|41199C76DF8CA804B7B8878D61228B9542A96AE4|topA]::aphA3 (citB-alsT)16) [pubmed|30957856]
Expression vectors
pGP2060: IPTG inducible expression, purification in ''E. coli'' with N-terminal Strep-tag, in [wiki|pGP172], available in [wiki|Jörg Stülke]'s lab
References
Reviews
Original Publications
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Time of last update: 2024-12-21 19:03:26
Author of last update: Jstuelk