Identification of a novel β-turn-rich repeat motif in the D hordeins of barley

Halford, Nigel G.; Tatham, Arthur S.; Sui, E.; Daroda, Lorenza; Dreyer, Thomas; Shewry, Peter R.

doi:10.1016/0167-4838(92)90313-3

Cited by 30 publications

(16 citation statements)

References 17 publications

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“…In addition to wheat, orthologous HMW glutenin subunits have also been found in Aegilops and rye species (William et al 1993;Wan et al 2000Wan et al , 2002De Bustos et al 2001;Liu et al 2003). In barley, the D-hordeins are structurally related to HMW glutenin subunits (Halford et al 1992).…”

Section: Introductionmentioning

confidence: 97%

Molecular characterization of HMW glutenin subunit allele 1Bx14: further insights into the evolution of Glu-B1-1 alleles in wheat and related species

Wan

Liu

et al. 2004

Theor Appl Genet

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1Bx14 is a member of the high molecular weight (HMW) glutenin subunits specified by wheat Glu-B1-1 alleles. In this work, we found that the full-length amino acid sequence of 1Bx14 and 1Bx20, the last two of the three cysteine residues, which are conserved in 1Bx7, 1Bx17 and homologous 1Ax and 1Dx subunits, were replaced by tyrosine residues. In the 5' flanking regions (-900 to -1,200 bp relative to the start codon), a novel miniature inverted-repeat transposable element insertion was present in 1Bx12 and 1Bx20 but not 1Bx7 and 1Bx17. 1Bx14 and 1Bx20 like alleles were readily found in tetraploid wheat subspecies but not several S genome containing Aegilops species. Phylogenetic analysis showed that the four molecularly characterized Glu-B1-1 alleles (1Bx7, 1Bx14, 1Bx17, 1Bx20) could be divided into two allelic lineages. The lineage represented by 1Bx7 and 1Bx17 was more ancient than the one represented by 1Bx14 and 1Bx20. Combined, our data establish that 1Bx14 and 1Bx20 represent a novel subclass of Glu-B1-1 alleles. Based on current knowledge, potential mechanism involved in the differentiation of two Glu-B1-1 lineages is discussed.

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Section: Introductionmentioning

confidence: 97%

Molecular characterization of HMW glutenin subunit allele 1Bx14: further insights into the evolution of Glu-B1-1 alleles in wheat and related species

Wan

Liu

et al. 2004

Theor Appl Genet

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“…Sla1p contains 26 repeats with the approximate consensus TG-GXXXPQ, in which X residues are most often aliphatic. Although secondary structure predictions fail to reveal an obvious structure for these repeats, it has been noted in wheat glutenins and barley hordeins that seven to nine amino acid repeats rich in glycine, proline, and glutamine can form a rod-like structure composed of regular ␤-turns (Field et al, 1987;Halford et al, 1992). Therefore, this region of Sla1p might have a similar structure.…”

Section: Sla1p Domain Structurementioning

confidence: 99%

“…The central third of Sla1p contains a putative SH3-domain binding consensus (Ren et al, 1993;Yu et al, 1994), and its C-terminal third is composed of 26 repeats with an approximate consensus TGGXXXPQ. This consensus repeat has homology to repeats in a range of proteins including the yeast protein Pan1p, a protein that has itself been postulated to be involved in organization of the actin cytoskeleton (Tang and Cai, 1996) and sea urchin sperm bindins (Gao et al, 1986;Minor et al, 1991), and also to the major plant structural proteins wheat glutenin and barley hordeins (Field et al, 1987;Halford et al, 1992).…”

Section: Introductionmentioning

confidence: 99%

Sla1p Is a Functionally Modular Component of the Yeast Cortical Actin Cytoskeleton Required for Correct Localization of Both Rho1p-GTPase and Sla2p, a Protein with Talin Homology

Ayscough

Eby

Lila

et al. 1999

MBoC

104

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SLA1 was identified previously in budding yeast in a genetic screen for mutations that caused a requirement for the actin-binding protein Abp1p and was shown to be required for normal cortical actin patch structure and organization. Here, we show that Sla1p, like Abp1p, localizes to cortical actin patches. Furthermore, Sla1p is required for the correct localization of Sla2p, an actin-binding protein with homology to talin implicated in endocytosis, and the Rho1p-GTPase, which is associated with the cell wall biosynthesis enzyme ␤-1,3-glucan synthase. Mislocalization of Rho1p in sla1 null cells is consistent with our observation that these cells possess aberrantly thick cell walls.Expression of mutant forms of Sla1p in which specific domains were deleted showed that the phenotypes associated with the full deletion are functionally separable. In particular, a region of Sla1p encompassing the third SH3 domain is important for growth at high temperatures, for the organization of cortical actin patches, and for nucleated actin assembly in a permeabilized yeast cell assay. The apparent redundancy between Sla1p and Abp1p resides in the C-terminal repeat region of Sla1p. A homologue of SLA1 was identified in Schizosaccharomyces pombe. Despite relatively low overall sequence homology, this gene was able to rescue the temperature sensitivity associated with a deletion of SLA1 in Saccharomyces cerevisiae.

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“…Purification of the hordein polypeptides reveals that they are complexed in larger aggregates by intermolecular disulfide bonds between Cys residues present in B, D, and ␥ hordein. Circular dichroism spectroscopy and small-angle x-ray-scattering studies of purified hordein polypeptides and synthetic oligopeptides indicate that C and D hordeins are rod-shaped molecules in an extended ␤-turn helix structure (Halford et al, 1992;I'Anson et al, 1992). The ability to express a recombinant C hordein and to refold it to its native conformation (Tamas et al, 1994) provides the first opportunity, to our knowledge, to study the degradation of a native substrate by a barley Cys EP.…”

mentioning

confidence: 99%

“…Purification of the hordein polypeptides reveals that they are complexed in larger aggregates by intermolecular disulfide bonds between Cys residues present in B, D, and ␥ hordein. Circular dichroism spectroscopy and small-angle x-ray-scattering studies of purified hordein polypeptides and synthetic oligopeptides indicate that C and D hordeins are rod-shaped molecules in an extended ␤-turn helix structure (Halford et al, 1992;Chemicals E-64, ␤-mercaptoethanol, papain (2ϫ recrystallized), N-CBZ-Phe-Arg-AMC, Cys, and buffers were purchased from Sigma.…”

mentioning

confidence: 99%

Substrate Specificity of Barley Cysteine Endoproteases EP-A and EP-B1

Davy¹,

Svendsen²,

Sørensen³

et al. 1998

Plant Physiology

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The cysteine endoproteases (EP)-A and EP-B were purified from green barley (Hordeum vulgare L.) malt, and their identity was confirmed by N-terminal amino acid sequencing. EP-B cleavage sites in recombinant type-C hordein were determined by N-terminal amino acid sequencing of the cleavage products, and were used to design internally quenched, fluorogenic peptide substrates. Tetrapeptide substrates of the general formula 2-aminobenzoyl-P 2 -P 1 -P 1 -P 2 -tyrosine(NO 2 )-aspartic acid, in which cleavage occurs between P 1 and P 1 , showed that the cysteine EPs preferred phenylalanine, leucine, or valine at P 2 . Arginine was preferred to glutamine at P 1 , whereas proline at P 2 , P 1 , or P 1 greatly reduced substrate kinetic specificity. Enzyme cleavage of C hordein was mainly determined by the primary sequence at the cleavage site, because elongation of substrates, based on the C hordein sequence, did not make them more suitable substrates. Site-directed mutagenesis of C hordein, in which serine or proline replaced leucine, destroyed primary cleavage sites. EP-A and EP-B were both more active than papain, mostly because of their much lower K m values.Two EPs known to play a central role in the breakdown of barley (Hordeum vulgare L.) endosperm storage proteins (hordeins) are Cys EPs designated EP-A (Koehler and Ho, 1990a) and EP-B (Koehler and Ho, 1988). They are secreted by the scutellum and aleurone layer into the starchy endosperm during germination in response to GA 3 (Koehler and Ho, 1990b;Marttila et al., 1995). EP-B has an apparent molecular mass of 30 kD, is identical to MEP-1 (Phillips and Wallace, 1989), and has a possible homolog with an apparent molecular mass of 31 kD (Zhang and Jones, 1996). The substrate specificity of this EP-B has been determined from the cleavage patterns of small proteins such as hordothionin, levitide, and cholecystokinin (Poulle and Jones, 1988;Zhang and Jones, 1996). There is little information about the substrate specificity of EP-A, although both EP-A and EP-B have been shown to digest hordein (Phillips and Wallace, 1989; Ho 1990a, 1990b). Characterization of the substrate specificity of barley Cys EPs provides an essential basis for an understanding of the activation of ␤-amylase by MEP-1 (ϭ EP-B) (Guerin et al., 1992) and limit dextrinase (Sissons, 1996) during germination, in which these enzymes are released (and activated) from bound and latent forms by proteolytic cleavage.Hordeins are unusual proteins, the amino acid composition and water insolubility of which present special problems as protease substrates. Pro and Gln comprise 40% of the total amino acids, and Pro causes particular problems for EPs, especially when it is at the protease scissile bond P 1 -P 1 Ј. (The substrate positions are denoted P i , . . . , P 2 , P 1 , P 1 Ј, P 2 Ј, . . . , P j , in correspondence with the binding subsites S i , etc., according to Berger and Schechter 1970). Hordeins, which are stored as compact protein bodies within the vacuoles of endosperm cells, comprise four major clas...

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Identification of a novel β-turn-rich repeat motif in the D hordeins of barley

Cited by 30 publications

References 17 publications

Molecular characterization of HMW glutenin subunit allele 1Bx14: further insights into the evolution of Glu-B1-1 alleles in wheat and related species

Molecular characterization of HMW glutenin subunit allele 1Bx14: further insights into the evolution of Glu-B1-1 alleles in wheat and related species

Sla1p Is a Functionally Modular Component of the Yeast Cortical Actin Cytoskeleton Required for Correct Localization of Both Rho1p-GTPase and Sla2p, a Protein with Talin Homology

Substrate Specificity of Barley Cysteine Endoproteases EP-A and EP-B1

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