A Rapid Fluorescence Bioassay for the Determination of Selenium on Agar Plates

Liu, Zesheng; Reches, Myriam; Engelberg‐Kulka, Hanna

doi:10.1006/abio.1996.9857

Cited by 5 publications

(3 citation statements)

References 7 publications

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“…Immediately downstream from the selenocysteine specifying UGA in the mRNA of each of these polypeptides is found a SECIS that has been described to consist at least 40 nucleotides capable of forming a stem-loop RNA structure. The insertion of a DNA segment including this specific SECIS into a heterologous gene like lacZ, results in the incorporation of selenocysteine into the corresponding polypeptide [13,18,33,34,40,47,48]. In addition to the presence of the SECIS, a number of trans elements are also required, including tRNA Sec (SelC), which is a specialized tRNA containing a UCA anticodon [30].…”

Section: Introductionmentioning

confidence: 99%

An extended Escherichia coli “Selenocysteine Insertion Sequence” (SECIS) as a multifunctional RNA structure

Engelberg‐Kulka

Liu

et al. 2001

BioFactors

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The genetic code, once thought to be rigid, has been found to permit several alternatives in its reading. Interesting alternative relates to the function of the UGA codon. Usually, it acts as a stop codon, but it can also direct the incorporation of the amino acid selenocysteine into a polypeptide. UGA-directed selenocysteine incorporation requires a cis-acting mRNA element called the "selenocysteine insertion sequence" (SECIS) that can form a stem-loop RNA structure. Here we discuss our investigation on the E. coli SECIS. This includes the follows: 1) The nature of the minimal E. coli SECIS. We found that in E. coli only the upper-stem and loop of 17 nucleotides of the SECIS is necessary for selenocysteine incorporation on the condition that it is located in the proper distance from the UGA [34]; 2) The upper stem and loop structure carries a bulged U residue that is required for selenocysteine incorporation [34] because of its interaction with SelB; and 3) We described an extended fdhF SECIS that includes the information for an additional function: The prevention of UGA readthrough under conditions of selenium deficiency [35]. This information is contained in a short mRNA region consisting of a single C residue adjacent to the UGA on its downstream side, and an additional segment consisting of the six nucleotides immediately upstream from it. These two regions act independently and additively and probably through different mechanisms. The single C residue acts as itself; the upstream region acts at the level of the two amino acids, arginine and valine, for which it codes. These two codons at the 5' side of the UGA correspond to the ribosomal E and P sites. Finally, we present a model for the E. coli fdhF SECIS as a multifunctional RNA structure containing three functional elements. Depending on the availability of selenium the SECIS enables one of two alternatives for the translational machinery: Either selenocysteine incorporation into a polypeptide or termination of the polypeptide chain.

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Section: Introductionmentioning

confidence: 99%

An extended Escherichia coli “Selenocysteine Insertion Sequence” (SECIS) as a multifunctional RNA structure

Engelberg‐Kulka

Liu

et al. 2001

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“…Immediately downstream from the selenocysteine specifying UGA in the mRNA of each of these polypeptides is found a SECIS that has been described as consisting of at least 40 nucleotides (nt) capable of forming a stem-loop RNA structure. Insertion of a DNA segment directing this specific SECIS into a heterologous gene such as lacZ results in the incorporation of selenocysteine into the corresponding polypeptide (9,12,(14)(15)(16)(17). A number of trans elements are also required, including tRNA Sec (SelC), which is a specialized tRNA containing a UCA anticodon (18).…”

Section: Introductionmentioning

confidence: 99%

The nature of the minimal 'selenocysteine insertion sequence' (SECIS) in Escherichia coli

Liu

Reches

Groisman

et al. 1998

Nucleic Acids Research

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The UGA codon, usually a stop codon, can also direct the incorporation into a protein of the modified amino acid selenocysteine. This UGA decoding process requires a cis -acting mRNA element called 'selenocysteine insertion sequence' (SECIS) that can form a stem-loop structure. In Escherichia coli the SECIS of the selenoprotein formate dehydrogenase (FdhH) mRNA has been previously described to consist of at least 40 nucleotides following the UGA codon. Here we determined the nature of the minimal SECIS required for the in vivo UGA-directed selenocysteine incorporation in E.coli . Our study is based on extensive mutational analysis of the fdhF SECIS DNA located in a lac' Z fusion. We found that the whole stem-loop RNA structure of the E.coli fdhF SECIS previously described is not required for the UGA-directed selenocysteine incorporation in vivo . Rather, only its upper stem-loop structure of 17 nucleotides is necessary on the condition that it is located in a proper distance (11 nucleotides) from the UGA codon. Based on these observations, we present a new model for the minimal E.coli SECIS.

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“…The SeCys is incorporated into the polypeptide chain due to an in-frame opaI (UGA) codon specific for SeCys incorporation [126,127]. In Bacteria, the distinction between a SeCys insertion and a stop codon depends on the 40-base sequence downstream of the UGA codon [128]. This sequence fold into a stem-loop structure called the SECIS element.…”

Section: Genes Organization and Physiological Roles Of Fdhsmentioning

confidence: 99%

Periplasmic nitrate reductases and formate dehydrogenases: Biological control of the chemical properties of Mo and W for fine tuning of reactivity, substrate specificity and metabolic role

González

Rivas

Mota

et al. 2013

Coordination Chemistry Reviews

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A Rapid Fluorescence Bioassay for the Determination of Selenium on Agar Plates

Cited by 5 publications

References 7 publications

An extended Escherichia coli “Selenocysteine Insertion Sequence” (SECIS) as a multifunctional RNA structure

An extended Escherichia coli “Selenocysteine Insertion Sequence” (SECIS) as a multifunctional RNA structure

The nature of the minimal 'selenocysteine insertion sequence' (SECIS) in Escherichia coli

Periplasmic nitrate reductases and formate dehydrogenases: Biological control of the chemical properties of Mo and W for fine tuning of reactivity, substrate specificity and metabolic role

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