Effects of <scp>FlrBC</scp> on flagellar biosynthesis of <scp><i>S</i></scp><i>hewanella oneidensis</i>

Shi, Miaomiao; Gao, Tong; Ju, Lin; Yao, Yanlai; Gao, Haichun

doi:10.1111/mmi.12731

Cited by 39 publications

(85 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Notably, without IPTG, slight growth of the ⌬desA ⌬fabB strain was observed (Fig. 4A), which is due to the leakiness of the promoter (21,22). The detrimental effect of excess FabF1 was confirmed in the wild-type strain (Fig.…”

Section: Resultsmentioning

confidence: 63%

“…In order to assess the effects of FabF1 and FabF2 of varying concentrations on growth and morphology, their coding genes were placed under the control of the isopropyl-␤-D-thiogalactopyranoside (IPTG)-inducible P tac promoter within pHGE-Ptac (20). While the P tac promoter within the vector in S. oneidensis is slightly leaky, displaying an activity of ϳ50 Miller units in the absence of IPTG, its strength increases proportionally with IPTG levels ranging from 0.001 to 1 mM, showing an activity of about 8,000 Miller units with 1 mM IPTG (21,22).…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Suppression of fabB Mutation by fabF1 Is Mediated by Transcription Read-through in Shewanella oneidensis

Quanfei

et al. 2016

J Bacteriol

Self Cite

View full text Add to dashboard Cite

As type II fatty acid synthesis is essential for the growth of Escherichia coli, its many components are regarded as potential targets for novel antibacterial drugs. Among them, ␤-ketoacyl-acyl carrier protein (ACP) synthase (KAS) FabB is the exclusive factor for elongation of the cis-3-decenoyl-ACP (cis-3-C 10 -ACP). In our previous study, we presented evidence to suggest that this may not be the case in Shewanella oneidensis, an emerging model gammaproteobacterium renowned for its respiratory versatility. Here, we identified FabF1, another KAS, as a functional replacement for FabB in S. oneidensis. In fabB ؉ or desA ؉ (encoding a desaturase) cells, which are capable of making unsaturated fatty acids (UFA), FabF1 is barely produced. However, UFA auxotroph mutants devoid of both fabB and desA genes can be spontaneously converted to suppressor strains, which no longer require exogenous UFAs for growth. Suppression is caused by a TGTTTT deletion in the region upstream of the fabF1 gene, resulting in enhanced FabF1 production. We further demonstrated that the deletion leads to transcription read-through of the terminator for acpP, an acyl carrier protein gene immediately upstream of fabF1. There are multiple tandem repeats in the region covering the terminator, and the TGTTTT deletion, as well as others, compromises the terminator efficacy. In addition, FabF2 also shows an ability to complement the FabB loss, albeit substantially less effectively than FabF1. IMPORTANCEIt has been firmly established that FabB for UFA synthesis via type II fatty acid synthesis in FabA-containing bacteria such as E. coli is essential. However, S. oneidensis appears to be an exception. In this bacterium, FabF1, when sufficiently expressed, is able to fully complement the FabB loss. Importantly, such a capability can be obtained by spontaneous mutations, which lead to transcription read-through. Therefore, our data, by identifying the functional overlap between FabB and FabFs, provide new insights into the current understanding of KAS and help reveal novel ways to block UFA synthesis for therapeutic purposes. The de novo fatty acid synthesis (FAS) pathway, namely, type II, is the predominant, if not exclusive, route for endogenous production of fatty acids (1). The FAS pathway, the current knowledge of which derives mainly from the model organism Escherichia coli, is highly conserved in bacteria. Central to the pathway are reactions catalyzed by ␤-ketoacyl-acyl carrier protein (ACP) synthases (KAS), including FabH, FabB, and FabF. FabH is responsible for the condensation of an acyl coenzyme A (acylCoA) unit and a malonyl-acyl carrier protein (malonyl-ACP) unit, but cannot work with acetyl-ACP, the substrate of FabB and FabF; as a consequence, FabH could not function as a replacement for FabB or FabF (1). While FabB and FabF are exchangeable in elongation of saturated intermediates, each catalyzes a reaction with the unsaturated branch that the other cannot or at least much less effectively (2) (Fig. 1). The key reaction catalyze...

show abstract

Section: Resultsmentioning

confidence: 63%

Section: Methodsmentioning

confidence: 99%

Suppression of fabB Mutation by fabF1 Is Mediated by Transcription Read-through in Shewanella oneidensis

Quanfei

et al. 2016

J Bacteriol

Self Cite

View full text Add to dashboard Cite

show abstract

“…To investigate whether nitrite inhibition of growth on fumarate, at least in part, is due to NapB in overabundance, we assessed effect of NapB in varying amounts on respiration of fumarate in the absence of nitrite. The napB gene was expressed in the wild-type strain under the control of IPTG-inducible promoter P tac , which is slightly leaky4950. Overexpression of the napB gene led to severe growth defect on fumarate (Fig.…”

Section: Resultsmentioning

confidence: 99%

NapB in excess inhibits growth of Shewanella oneidensis by dissipating electrons of the quinol pool

Jin

Zhang

Sun

et al. 2016

Sci Rep

Self Cite

View full text Add to dashboard Cite

Shewanella, a group of ubiquitous bacteria renowned for respiratory versatility, thrive in environments where various electron acceptors (EAs) of different chemical and physiological characteristics coexist. Despite being extensively studied, we still know surprisingly little about strategies by which multiple EAs and their interaction define ecophysiology of these bacteria. Previously, we showed that nitrite inhibits growth of the genus representative Shewanella oneidensis on fumarate and presumably some other CymA (quinol dehydrogenase)-dependent EAs by reducing cAMP production, which in turn leads to lowered expression of nitrite and fumarate reductases. In this study, we demonstrated that inhibition of fumarate growth by nitrite is also attributable to overproduction of NapB, the cytochrome c subunit of nitrate reductase. Further investigations revealed that excessive NapB per se inhibits growth on all EAs tested, including oxygen. When overproduced, NapB acts as an electron shuttle to dissipate electrons of the quinol pool, likely to extracellullar EAs, because the Mtr system, the major electron transport pathway for extracellular electron transport, is implicated. The study not only sheds light on mechanisms by which certain EAs, especially toxic ones, impact the bacterial ecophysiology, but also provides new insights into how electron shuttle c-type cytochromes regulate multi-branched respiratory networks.

show abstract

“…In addition, SoOxyR L197P mutant is found to be locked into the oxidized state (25) (18,19). Because the promoter is slightly leaky (26,27) Fig. 2A).…”

Section: Resultsmentioning

confidence: 99%

Defining the binding determinants of Shewanella oneidensis OxyR: Implications for the link between the contracted OxyR regulon and adaptation

Wan

Kong

Gao

2018

Journal of Biological Chemistry

Self Cite

View full text Add to dashboard Cite

show abstract

Effects of FlrBC on flagellar biosynthesis of Shewanella oneidensis

Cited by 39 publications

References 55 publications

Suppression of fabB Mutation by fabF1 Is Mediated by Transcription Read-through in Shewanella oneidensis

Suppression of fabB Mutation by fabF1 Is Mediated by Transcription Read-through in Shewanella oneidensis

NapB in excess inhibits growth of Shewanella oneidensis by dissipating electrons of the quinol pool

Defining the binding determinants of Shewanella oneidensis OxyR: Implications for the link between the contracted OxyR regulon and adaptation

Contact Info

Product

Resources

About