Overexpression of endonuclease III protects <i>Escherichia coli</i> mutants defective in alkylation repair against lethal effects of methylmethanesulphonate

Eide, Lars; Fosberg, Ellen; Hoff, E.; Seeberg, Erling

doi:10.1016/s0014-5793(01)02156-1

Cited by 2 publications

(3 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Saci_0385 codes for 3-hydroxy-isobutyrate (HIB) dehydrogenase, which is involved in valine degradation (38,41). The annotated, upregulated genes include Saci_1497, encoding endonuclease III, which is involved in DNA repair (15), and Saci_1494, encoding a type II/IV secretion system protein suspected to be involved in archaeal flagellar synthesis (Table 2). These differentially expressed genes provided little information about the likely mechanism or regulation of simultaneous metabolism of glucose and xylose.…”

Section: Resultsmentioning

confidence: 99%

“…The others that were upregulated mostly encoded hypothetical proteins, many of which are conserved only in Sulfolobus species or archaea. Some of the few annotated genes coded for proteins like endonuclease III (Saci_1497), which is involved in DNA repair (15), and type II/IV secretion system protein (Saci_1494), which is likely involved in flagellar biosynthesis. The relevance of these proteins to simultaneous catabolism remains unknown, and the absence of well-annotated orthologs of the differentially expressed genes made it difficult to assign a function to them.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Absence of Diauxie during Simultaneous Utilization of Glucose and Xylose bySulfolobus acidocaldarius

et al. 2011

View full text Add to dashboard Cite

Sulfolobus acidocaldarius utilizes glucose and xylose as sole carbon sources, but its ability to metabolize these sugars simultaneously is not known. We report the absence of diauxie during growth of S. acidocaldarius on glucose and xylose as co-carbon sources. The presence of glucose did not repress xylose utilization. The organism utilized a mixture of 1 g/liter of each sugar simultaneously with a specific growth rate of 0.079 h ؊1 and showed no preference for the order in which it utilized each sugar. The organism grew faster on 2 g/liter xylose (0.074 h ؊1 ) as the sole carbon source than on an equal amount of glucose (0.022 h ؊1 ). When grown on a mixture of the two carbon sources, the growth rate of the organism increased from 0.052 h ؊1 to 0.085 h ؊1 as the ratio of xylose to glucose increased from 0.25 to 4. S. acidocaldarius appeared to utilize a mixture of glucose and xylose at a rate roughly proportional to their concentrations in the medium, resulting in complete utilization of both sugars at about the same time. Gene expression in cells grown on xylose alone was very similar to that in cells grown on a mixture of xylose and glucose and substantially different from that in cells grown on glucose alone. The mechanism by which the organism utilized a mixture of sugars has yet to be elucidated.Sulfolobus acidocaldarius is a hyperthermophilic archaeon that grows optimally at 75°C and pH 2.0 to 3.0 (10, 20, 24) and has been shown to utilize a broad range of sugars (20,24). Numerous studies have shown that bacteria as well as eukaryotes sequentially utilize individual sugars when grown on a mixture of sugars. These organisms preferentially utilize the sugar that best supports their growth (mostly glucose) by repressing the utilization of other sugars in the growth medium until the preferential sugar is completely consumed. This phenomenon, termed "carbon catabolite repression" (CCR), or "diauxie," is characterized by a diphasic growth pattern when an organism is grown on a mixture of glucose and other sugars. Most studies of CCR have focused mainly on bacterial or eukaryotic systems. However, a few studies have reported that the presence of glucose in a growth medium represses the metabolism of other sugars in species closely related to Sulfolobus solfataricus via a mechanism that is similar to CCR (22,23,25,34).S. acidocaldarius metabolizes the smallest number of sugars of all known Sulfolobus species, but the sugars metabolized by the organism include glucose and xylose, the key constituents of ligno-cellulose (cellulosic) biomass (20,24,37). The lack of diauxie on 5-and 6-carbon sugars and the ability to grow at high temperature and low pH are excellent characteristics for a host that produces biofuel from cellulosic biomass deconstructed by acidic and/or high-temperature pretreatment methods. The production of biofuels from cellulosic biomass as an alternative to fossil fuels has received increased attention in the past few years. However, the development of microbial system(s) that can efficiently and...

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Absence of Diauxie during Simultaneous Utilization of Glucose and Xylose bySulfolobus acidocaldarius

et al. 2011

View full text Add to dashboard Cite

show abstract

“…In vitro the Fpg and Nth proteins can cleave dR via b-elimination with high ef®ciency (66,67) and may participate in repair of AP sites. However, it was shown that fpg and nth, in contrast with xth and xth nfo mutants, are not sensitive to alkylation DNA damage, suggesting that DNA glycosylases/AP lyases play a minor role in repair of AP sites in vivo (70,71). Interestingly, we found a signi®cant 5-fold increase of dRinduced reversion frequency in E.coli fpg nth mutant, suggesting that the DNA glycosylases/AP lyases suppress mutations induced by dR in vivo.…”

Section: Discussionmentioning

confidence: 62%

2'-Deoxyribonolactone lesion produces G->A transitions in Escherichia coli

Faure

Constant²,

Dumy³

et al. 2004

Nucleic Acids Research

View full text Add to dashboard Cite

2'-deoxyribonolactone (dL) is a C1'-oxidized abasic site damage generated by a radical attack on DNA. Numerous genotoxic agents have been shown to produce dL including UV and gamma-irradiation, ene-dye antibiotics etc. At present the biological consequences of dL present in DNA have been poorly documented, mainly due to the lack of method for introducing the lesion in oligonucleotides. We have recently designed a synthesis of dL which allowed investigation of the mutagenicity of dL in Escherichia coli by using a genetic reversion assay. The lesion was site-specifically incorporated in a double-stranded bacteriophage vector M13G*1, which detects single-base-pair substitutions at position 141 of the lacZalpha gene by a change in plaque color. In E.coli JM105 the dL-induced reversion frequency was 4.7 x 10(-5), similar to that of the classic abasic site 2'-deoxyribose (dR). Here we report that a dL residue in a duplex DNA codes mainly for thymidine. The processing of dL in vivo was investigated by measuring lesion-induced mutation frequencies in DNA repair deficient E.coli strains. We showed a 32-fold increase in dL-induced reversion rate in AP endonuclease deficient (xth nfo) mutant compared with wild-type strain, indicating that the Xth and Nfo AP endonucleases participate in dL repair in vivo.

show abstract

Overexpression of endonuclease III protects Escherichia coli mutants defective in alkylation repair against lethal effects of methylmethanesulphonate

Cited by 2 publications

References 30 publications

Absence of Diauxie during Simultaneous Utilization of Glucose and Xylose bySulfolobus acidocaldarius

Absence of Diauxie during Simultaneous Utilization of Glucose and Xylose bySulfolobus acidocaldarius

2'-Deoxyribonolactone lesion produces G->A transitions in Escherichia coli

Contact Info

Product

Resources

About