SecAAA trimer is fully functional as SecAA dimer in the membrane: Existence of higher oligomers?

Wang, Hongyun; Ma, Yamin; Hsieh, Ying-Hsin; Yang, Hanfang; Li, Minyong; Wang, Binghe; Tai, Phang C.

doi:10.1016/j.bbrc.2014.03.116

Cited by 5 publications

(6 citation statements)

References 38 publications

(65 reference statements)

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“…2 A). Similar to previous data [46], when wild-type SecA was treated with EDC [22], several high molecular weight bands were observed at around 200 kDa and above (Fig. 2 B, lanes 2-4), representing different crosslinking species of SecA.…”

Section: Resultssupporting

confidence: 90%

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Characterization of the minimal length of functional SecA in Escherichia coli

You

Yang

et al. 2015

Biochemical and Biophysical Research Communications

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Previous studies showed that certain regions of E. coli SecA can be deleted from its N- and/or C-termini to complement a SecA amber ts mutant. In this study, we determined and characterized the dispensability of both ends of SecA molecules. With N-terminal intact or 9-aa deleted, 826aa (SecA1-826 and SecA10-826 respectively) is the minimum for complementation activity, while with N-terminus deleted by 2-21aa, SecA22-829 is the minimum. Further deletion at the C-terminus of SecA1-826/SecA10-826/SecA22-829 abolished the complementation activity in the cells. A hydrophobic amino acid is required for the 826th residue in the minimal-length SecAs. Chemical crosslinking and gel filtration result showed that both purified SecA22-828 and SecA22-829 could form a dimer. Moreover, the in vitro ATPase and protein translocation activities of SecA22-828 and SecA22-829 were similar, though lower than wild-type SecA. The active mutants had more truncated SecA in soluble than membrane-bound form, but was more stably embedded in membranes. In contrast, the inactive mutants tended to have truncated SecA more membrane-bound than soluble form, and were more loosely bound and easily chased out. Thus, the loss of complementation appears to be related to their altered subcellular localization and stability in the membranes. This study defines the substantial regions of N- and C-termini of SecA that may be deleted without losing complementation activity.

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Section: Resultssupporting

confidence: 90%

“…The C-terminal domain of SecA is involved in dimerization [22,25]. It has been reported that SecA 11-831 functions as a monomer [29] but has been disputed [24,28,46]. Deletion of the SecA C-terminus may affect its dimerization ability, thus impairing its complementation ability.…”

Section: Resultsmentioning

confidence: 99%

Characterization of the minimal length of functional SecA in Escherichia coli

You

Yang

et al. 2015

Biochemical and Biophysical Research Communications

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“…The domains required for pore formation are different from those required for the ion-channel and protein-translocation activities. Identification of different domains for ATPase, pore structure, channel activity and protein translocation support the idea that SecA functions at least as a dimer [ 15 , 27 , 39 , 56 , 70 , 71 ] and refs. therein) in the SecA-only channels.…”

Section: Discussionmentioning

confidence: 70%

Dissecting structures and functions of SecA-only protein-conducting channels: ATPase, pore structure, ion channel activity, protein translocation, and interaction with SecYEG/SecDF•YajC

et al. 2017

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SecA is an essential protein in the major bacterial Sec-dependent translocation pathways. E. coli SecA has 901 aminoacyl residues which form multi-functional domains that interact with various ligands to impart function. In this study, we constructed and purified tethered C-terminal deletion fragments of SecA to determine the requirements for N-terminal domains interacting with lipids to provide ATPase activity, pore structure, ion channel activity, protein translocation and interactions with SecYEG-SecDF•YajC. We found that the N-terminal fragment SecAN493 (SecA1-493) has low, intrinsic ATPase activity. Larger fragments have greater activity, becoming highest around N619-N632. Lipids greatly stimulated the ATPase activities of the fragments N608-N798, reaching maximal activities around N619. Three helices in amino-acyl residues SecA619-831, which includes the “Helical Scaffold” Domain (SecA619-668) are critical for pore formation, ion channel activity, and for function with SecYEG-SecDF•YajC. In the presence of liposomes, N-terminal domain fragments of SecA form pore-ring structures at fragment-size N640, ion channel activity around N798, and protein translocation capability around N831. SecA domain fragments ranging in size between N643-N669 are critical for functional interactions with SecYEG-SecDF•YajC. In the presence of liposomes, inactive C-terminal fragments complement smaller non-functional N-terminal fragments to form SecA-only pore structures with ion channel activity and protein translocation ability. Thus, SecA domain fragment interactions with liposomes defined critical structures and functional aspects of SecA-only channels. These data provide the mechanistic basis for SecA to form primitive, low-efficiency, SecA-only protein-conducting channels, as well as the minimal parameters for SecA to interact functionally with SecYEG-SecDF•YajC to form high-efficiency channels.

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“…SecA is a key component of the bacterial protein secretion (Sec) pathways. It is an ATPase-driven "motor," which couples the hydrolysis of ATP to the stepwise translocation of preproteins across the bacterial cytoplasmic membrane [5][6][7][8]. Because SecA is a conserved and essential protein in all bacteria and is absent in humans, it is considered as a promising antibacterial drug target.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and biological evaluation of novel 4-oxo-5-cyano thiouracil derivatives as SecA inhibitors

Bamba

Jin

Tai

et al. 2020

Heterocyclic Communications

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The continuous emergence of drug-resistant strains of bacteria poses an urgent risk to human health and dictates the need for new antimicrobials. Along this line, we have been working on developing inhibitors of SecA, a key component of the bacterial Sec-dependent secretion machinery. Herein, we describe the synthesis and antimicrobial evaluation of 6-oxo-1,6-dihydropyrimidine-5-carbonitrile derivatives as potential SecA inhibitors.

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SecAAA trimer is fully functional as SecAA dimer in the membrane: Existence of higher oligomers?

Cited by 5 publications

References 38 publications

Characterization of the minimal length of functional SecA in Escherichia coli

Characterization of the minimal length of functional SecA in Escherichia coli

Dissecting structures and functions of SecA-only protein-conducting channels: ATPase, pore structure, ion channel activity, protein translocation, and interaction with SecYEG/SecDF•YajC

Synthesis and biological evaluation of novel 4-oxo-5-cyano thiouracil derivatives as SecA inhibitors

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