Characterization of an opsin gene from the ascomycete Leptosphaeria maculans

Genome ◽  
2001 ◽  
Vol 44 (2) ◽  
pp. 167-171 ◽  
Author(s):  
Alexander Idnurm ◽  
Barbara J Howlett
Keyword(s):  
Leptosphaeria Maculans ◽  
Brassica Species ◽  
Binding Pocket ◽  
Opsin Gene ◽  
Amino Acid Residues ◽  
Blackleg Disease ◽  
Type Locus ◽  
Cloned Gene ◽  
Retinal Binding Pocket

An opsin gene (ops) has been characterized from Leptosphaeria maculans, the ascomycete that causes blackleg disease of Brassica species. This is the second opsin identified outside the archaeal and animal kingdoms. The gene encodes a predicted protein with high similarity (70.3%) and identity (53.3%) to the nop-1 opsin of another ascomycete Neurospora crassa. The L. maculans opsin also has identical amino acid residues in 20 of the 22 residues in the retinal-binding pocket of archaeal opsins. Opsin, on the fourth largest chromosome of L. maculans and 22 cM from the mating type locus, is the first cloned gene to be mapped in L. maculans. Opsin is transcribed at high levels in mycelia grown in the presence and absence of light; this pattern is in contrast with that of the N. crassa opsin, which is transcribed only in the light.Key words: opsin, Phoma lingam, Brassica napus.

Mapping genes for resistance to Leptosphaeria maculans in Brassica juncea

Genome ◽  
2006 ◽  
Vol 49 (1) ◽  
pp. 30-41 ◽  
Author(s):  
J A Christianson ◽  
S R Rimmer ◽  
A G Good ◽  
D J Lydiate
Keyword(s):  
Linkage Group ◽  
Brassica Juncea ◽  
Fragment Length Polymorphism ◽  
Leptosphaeria Maculans ◽  
Recessive Gene ◽  
Brassica Species ◽  
Blackleg Disease ◽  
Recessive Resistance ◽  
B Genome ◽  
Restriction Fragment Length

Blackleg disease of crucifers, caused by the fungus Leptosphaeria maculans, is a major concern to oilseed rape producers worldwide. Brassica species containing the B genome have high levels of resistance to blackleg. Brassica juncea F2 and first-backcross (B1) populations segregating for resistance to a PG2 isolate of L. maculans were created. Segregation for resistance to L. maculans in these populations suggested that resistance was controlled by two independent genes, one dominant and one recessive in nature. A map of the B. juncea genome was constructed using segregation in the F2 population of a combination of restriction fragment length polymorphism (RFLP) and microsatel lite markers. The B. juncea map consisted of 325 loci and was aligned with previous maps of the Brassica A and B genomes. The gene controlling dominant resistance to L. maculans was positioned on linkage group J13 based on segregation for resistance in the F2 population. This position was confirmed in the B1 population in which the resistance gene was definitively mapped in the interval flanked by pN199RV and sB31143F. The provisional location of the recessive gene controlling resistance to L. maculans on linkage group J18 was identified using a subset of informative F2 individuals.Key words: blackleg, B genome, phoma, recessive resistance.

scholarly journals Genome-Wide Identification and Analysis of VQ Motif-containing Gene Family in Brassica napus and Functional Characterization of BnMKS1 in Response to Leptosphaeria maculans

2020 ◽  
Author(s):  
Zhongwei Zou ◽  
Fei Liu ◽  
Shuanglong Huang ◽  
DILANTHA GERARD FERNANDO
Keyword(s):  
Brassica Napus ◽  
Gene Family ◽  
Functional Characterization ◽  
Leptosphaeria Maculans ◽  
Defense Responses ◽  
Marker Genes ◽  
Blackleg Disease ◽  
Genome Wide ◽  
A Genome

Proteins containing Valine-glutamine (VQ) motifs play important roles in plant growth and development, as well as in defense responses to both abiotic and biotic stresses. Blackleg disease, which is caused by Leptosphaeria maculans, is the most important disease in canola (Brassica napus L.) worldwide. H; however, the identification of B. napus VQs and their functions in response to blackleg disease have not yet been reported. In this study, we conducted a genome genome-wide identification and characterization of the VQ gene family in B. napus, including chromosome location, phylogenetic relations, gene structure, motif domain, synteny analysis, and cis-elements categorization of their promoter regions. To understand B. napus VQ gene function in response to blackleg disease, we overexpressed BnVQ7 (BnaA01g36880D, also known as the mitogen-activated protein kinase4 substrate1 (MKS1) gene) in a blackleg-susceptible canola variety Westar. Overexpression The overexpression of BnMKS1 in canola did not improve its resistance to blackleg disease at the seedling stage. H; however, transgenic canola plants overexpressing BnMKS1 displayed an enhanced resistance to L. maculans infection at the adult plant stage. Expression levels of downstream and defense marker genes in cotyledons increased significantly at the necrotrophic stage of L. maculans infection in the overexpression line of BnMKS1, suggesting that the SA salicylic acid (SA)- and jasmonic acid (JA )-mediated signaling pathways were both involved in the defense responses. Together, these results suggest that BnMKS1 might play an important role in the defense against L. maculans.

scholarly journals GENETIC ANALYSIS OF STAPHYLOCOCCAL NUCLEASE: IDENTIFICATION OF THREE INTRAGENIC "GLOBAL" SUPPRESSORS OF NUCLEASE-MINUS MUTATIONS

Genetics ◽  
1985 ◽  
Vol 110 (4) ◽  
pp. 539-555 ◽  
Author(s):  
David Shortle ◽  
Beth Lin
Keyword(s):  
Nuclease Activity ◽  
Staphylococcal Nuclease ◽  
Missense Mutations ◽  
Amino Acid Residues ◽  
Gene Encoding ◽  
Protein Coding ◽  
E Coli ◽  
Suppressor Mutations ◽  
Cloned Gene

ABSTRACT A collection of 77 unique missense mutations distributed across the gene encoding staphylococcal nuclease (nuc) has been assembled. These mutations were induced by random gap misrepair mutagenesis of the cloned gene and were identified in E. coli transformants expressing reduced levels of nuclease activity. Four nuc  - mutations which alter amino acid residues at positions outside of the active site region of the enzyme were submitted to a second round of mutagenesis, and characterization of several independent NUC+ isolates lead to the identification of three second-site suppressor mutations within the protein-coding sequence of the nuc gene. On separation from the mutation originally suppressed and recombination with a number of other nuc  - mutations, all three suppressors displayed the property of "global" suppression, i.e., phenotypic suppression of the nuclease-minus character of multiple different alleles. A simple and generally applicable strategy was used to obtain efficient homologous recombination between plasmids for purposes of mapping nuc  - mutations, mapping second-site suppressors and constructing double mutant combinations from pairs of single mutations.

Usefulness of winter canola (Brassica napus) race-specific resistance genes against blackleg (causal agent Leptosphaeria maculans) in southern Australian growing conditions

2011 ◽  
Vol 62 (2) ◽  
pp. 162 ◽  
Author(s):  
K. A. Light ◽  
N. N. Gororo ◽  
P. A. Salisbury
Keyword(s):  
Disease Resistance ◽  
Resistance Genes ◽  
Leptosphaeria Maculans ◽  
Brassica Species ◽  
Superior Performance ◽  
Adult Plant ◽  
Control Line ◽  
Blackleg Disease ◽  
Blackleg Resistance ◽  
Spring Canola

Studies on the blackleg resistance of Brassica lines containing known race-specific, Rlm resistance genes can provide information on the potential use of these genes in the genetic improvement of Australian spring canola lines. Lines of four Brassica species (winter B. napus, B. nigra, B. juncea, B. rapa) containing one or more known specific Rlm genes were assessed for seedling and adult plant survival, on infected stubble derived from crops of both polygenic and B. rapa ssp. sylvestris resistance types, to determine their potential usefulness as sources of blackleg disease resistance in diverse environments in southern Australia. Seedling and adult plant resistance of lines differed depending on the stubble type used. The seedling and adult plant blackleg resistance of several lines containing the resistance genes Rlm1, Rlm1/Rlm3, Rlm7, and Rlm10 was consistently higher than the control line, AV-Sapphire, which carries polygenic resistance. The superior performance of these lines indicates that winter B. napus and B. nigra lines have outstanding potential for improving blackleg disease resistance under Australian conditions.

scholarly journals The laterally acquired GH5 ZgEngAGH5_4 from the marine bacterium Zobellia galactanivorans is dedicated to hemicellulose hydrolysis

2018 ◽  
Vol 475 (22) ◽  
pp. 3609-3628 ◽  
Author(s):  
Jonathan Dorival ◽  
Sophie Ruppert ◽  
Melissa Gunnoo ◽  
Adam Orłowski ◽  
Maylis Chapelais-Baron ◽  
...  
Keyword(s):  
Heterotrophic Bacteria ◽  
Carbon Sources ◽  
Binding Pocket ◽  
Catalytic Triad ◽  
Marine Macroalgae ◽  
Amino Acid Residues ◽  
Glucose Binding ◽  
Marine Heterotrophic Bacteria ◽  
Binding Subsites

Cell walls of marine macroalgae are composed of diverse polysaccharides that provide abundant carbon sources for marine heterotrophic bacteria. Among them, Zobellia galactanivorans is considered as a model for studying algae–bacteria interactions. The degradation of typical algal polysaccharides, such as agars or alginate, has been intensively studied in this model bacterium, but the catabolism of plant-like polysaccharides is essentially uncharacterized. Here, we identify a polysaccharide utilization locus in the genome of Z. galactanivorans, induced by laminarin (β-1,3-glucans), and containing a putative GH5 subfamily 4 (GH5_4) enzyme, currently annotated as a endoglucanase (ZgEngAGH5_4). A phylogenetic analysis indicates that ZgEngAGH5_4 was laterally acquired from an ancestral Actinobacteria. We performed the biochemical and structural characterization of ZgEngAGH5_4 and demonstrated that this GH5 is, in fact, an endo-β-glucanase, most active on mixed-linked glucan (MLG). Although ZgEngAGH5_4 and GH16 lichenases both hydrolyze MLG, these two types of enzymes release different series of oligosaccharides. Structural analyses of ZgEngAGH5_4 reveal that all the amino acid residues involved in the catalytic triad and in the negative glucose-binding subsites are conserved, when compared with the closest relative, the cellulase EngD from Clostridium cellulovorans, and some other GH5s. In contrast, the positive glucose-binding subsites of ZgEngAGH5_4 are different and this could explain the preference for MLG, with respect to cellulose or laminarin. Molecular dynamics computer simulations using different hexaoses reveal that the specificity for MLG occurs through the +1 and +2 subsites of the binding pocket that display the most important differences when compared with the structures of other GH5_4 enzymes.

Characterization of an opsin gene from the ascomycete Leptosphaeria maculans

Genome ◽  
2001 ◽  
Vol 44 (2) ◽  
pp. 167-171 ◽  
Author(s):  
Alexander Idnurm ◽  
Barbara J. Howlett
Keyword(s):  
Leptosphaeria Maculans ◽  
Opsin Gene

scholarly journals Mating Type in Chlamydomonas Is Specified by mid, the Minus-Dominance Gene

Genetics ◽  
1997 ◽  
Vol 146 (3) ◽  
pp. 859-869 ◽  
Author(s):  
Patrick J Ferris ◽  
Ursula W Goodenough
Keyword(s):  
Transcription Factor ◽  
Mating Type ◽  
Codon Bias ◽  
Leucine Zipper ◽  
Laboratory Strain ◽  
Leucine Zipper Motif ◽  
Type Locus ◽  
Diploid Cells ◽  
Necessary And Sufficient

Diploid cells of Chlamydomonas reinhardtii that are heterozygous at the mating-type locus (mt  +/mt  –) differentiate as minus gametes, a phenomenon known as minus dominance. We report the cloning and characterization of a gene that is necessary and sufficient to exert this minus dominance over the plus differentiation program. The gene, called mid, is located in the rearranged (R) domain of the mt  – locus, and has duplicated and transposed to an autosome in a laboratory strain. The imp11 mt  – mutant, which differentiates as a fusion-incompetent plus gamete, carries a point mutation in mid. Like the fus1 gene in the mt  + locus, mid displays low codon bias compared with other nuclear genes. The mid sequence carries a putative leucine zipper motif, suggesting that it functions as a transcription factor to switch on the minus program and switch off the plus program of gametic differentiation. This is the first sex-determination gene to be characterized in a green organism.

scholarly journals Identification and characterization of amphibian SLC26A5 using RNA-Seq

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Zhongying Wang ◽  
Qixuan Wang ◽  
Hao Wu ◽  
Zhiwu Huang
Keyword(s):  
Amino Acid ◽  
Inner Ear ◽  
Hair Cells ◽  
Rana Catesbeiana ◽  
Site Directed Mutagenesis ◽  
Amino Acid Residues ◽  
Rna Seq ◽  
American Bullfrog ◽  
Frog Species

Abstract Background Prestin (SLC26A5) is responsible for acute sensitivity and frequency selectivity in the vertebrate auditory system. Limited knowledge of prestin is from experiments using site-directed mutagenesis or domain-swapping techniques after the amino acid residues were identified by comparing the sequence of prestin to those of its paralogs and orthologs. Frog prestin is the only representative in amphibian lineage and the studies of it were quite rare with only one species identified. Results Here we report a new coding sequence of SLC26A5 for a frog species, Rana catesbeiana (the American bullfrog). In our study, the SLC26A5 gene of Rana has been mapped, sequenced and cloned successively using RNA-Seq. We measured the nonlinear capacitance (NLC) of prestin both in the hair cells of Rana’s inner ear and HEK293T cells transfected with this new coding gene. HEK293T cells expressing Rana prestin showed electrophysiological features similar to that of hair cells from its inner ear. Comparative studies of zebrafish, chick, Rana and an ancient frog species showed that chick and zebrafish prestin lacked NLC. Ancient frog’s prestin was functionally different from Rana. Conclusions We mapped and sequenced the SLC26A5 of the Rana catesbeiana from its inner ear cDNA using RNA-Seq. The Rana SLC26A5 cDNA was 2292 bp long, encoding a polypeptide of 763 amino acid residues, with 40% identity to mammals. This new coding gene could encode a functionally active protein conferring NLC to both frog HCs and the mammalian cell line. While comparing to its orthologs, the amphibian prestin has been evolutionarily changing its function and becomes more advanced than avian and teleost prestin.

Characterization of the Acyl Substrate Binding Pocket of Acetyl-CoA Synthetase†

Biochemistry ◽  
2006 ◽  
Vol 45 (38) ◽  
pp. 11482-11490 ◽  
Author(s):  
Cheryl Ingram-Smith ◽  
Barrett I. Woods ◽  
Kerry S. Smith
Keyword(s):  
Substrate Binding ◽  
Binding Pocket ◽  
Substrate Binding Pocket ◽  
Acetyl Coa
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