cDNA sequence and tissue-specific expression of an anionic flax peroxidase

Genome ◽  
1994 ◽  
Vol 37 (1) ◽  
pp. 137-147 ◽  
Author(s):  
Franz Omann ◽  
Normand Beaulieu ◽  
Hugh Tyson

A flax (Linum usitatissimum L.) λgt10 cDNA library was screened with a probe coding for the amino terminus of a flax peroxidase. The probe was generated by PCR amplification of the library with one of the λgt10 sequencing primers and a mixed oligonucleotide derived from a well-conserved amino acid region (distal heme ligand) found in all plant peroxidases. A positive clone (FLXPER2) was isolated and characterized. The cDNA contains 1153 nucleotides, excluding the poly(A) tail, and encodes a mature protein of 297 amino acids with a molecular mass of 31.9 kDa. The mature protein's amino acid sequence contains three highly conserved regions, two of which contain histidine ligands for the heme group. The deduced amino acid sequence has nine cysteine residues. Eight are identically located to those of horseradish C peroxidase, which participate in four disulfide bridges; these cysteines are highly conserved in all plant peroxidases. One potential N-glycosylation site (Asn-X-Thr/Ser) is present. The predicted pI value of 4.5 identifies FLXPER2 as an anionic peroxidase. Northern blot analysis shows that its mRNA expression is unique to stem tissue. Amino acid sequence comparisons show high similarity between FLXPER2 and peanut, rice, and tobacco peroxidases.Key words: flax peroxidase cDNA, PCR, Northern analysis, sequence relationships.

1996 ◽  
Vol 23 (6) ◽  
pp. 773 ◽  
Author(s):  
F Omann ◽  
H Tyson

A flax (Linum usitatissimum L.) peroxidase cDNA (FLXPER1) was isolated from a �gt10 library made from RNA derived from shoot tissue of the cultivar Stormont Cirrus, by screening with probes encoding amino termini of flax peroxidases. The probes were obtained by PCR amplification of the library with the �gt10 reverse primer 5'CTTATGAGTATTTCTTCCAGGGTA3' flanking the Eco RI cloning site, and a mixed oligonucleotide derived from the catalytic domain (HFHDCFV) found in all plant peroxidases. FLXPER1 is the second flax peroxidase to be so isolated and described, following the previously documented FLXPER2 (Omann et al. 1994, Genome 37, 137-147). These two cDNAs are the completely sequenced members of a family currently encompassing FLXPER1 to FLXPER4, all isolated from the same �gt10 library. FLXPER3 and 4 will be separately described and related to FLXPER1, 2. The FLXPER1 deduced amino acid sequence reveals a signal peptide of 27 amino acids, and an anionic mature protein with seven potential N-linked glycosylation sites in its 332 amino acids (38.25 kDa; pI 4.38). The FLXPER1 C terminus is similar to plant peroxidases with a putative C-terminal vacuolar targeting signal, but also contains amino acid motifs with striking homologies to the membrane anchoring motifs of a pea blue copper type protein correlated with lignin deposition. Northern blot analysis demonstrated its stem specific expression. Southern blots suggested one to five copies of FLXPER1 in the flax genome, compared with one to two for FLXPER2. FLXPER1 resembles cucumber, poplar and tobacco amino acid sequences; its asymmetry in codon usage coincides with that of other dicotyledon peroxidases, i.e. much lower than in monocotyledon peroxidases.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Arbind Kumar ◽  
Jagdeep Kaur

The genome of Mycobacterium is rich in GC content and poses problem in amplification of some genes, especially those rich in the GC content in terminal regions, by standard/routine PCR procedures. Attempts have been made to amplify three GC rich genes of Mycobacterium sp. (Rv0519c and Rv0774c from M. tuberculosis and ML0314c from M. leprae). Out of these three genes, Rv0774c gene was amplified with normal primers under standard PCR conditions, while no amplification was observed in case of Rv0519c and ML0314c genes. In the present investigation a modified primer based approach was successfully used for amplification of GC rich sequence of Rv0519c through codon optimization without changing the native amino acid sequence. The strategy was successfully confirmed by redesigning the standard primers with similar modifications followed by amplification of ML0314c gene.


2000 ◽  
Vol 203 (22) ◽  
pp. 3411-3423 ◽  
Author(s):  
Z. Zhang ◽  
D. Chen ◽  
M.G. Wheatly

The discontinuous pattern of muscle growth during the moulting cycle of a freshwater crustacean (the crayfish Procambarus clarkii) was used as a model system to examine the regulation of the expression of Sarco/Endoplasmic Reticulum Ca(2+)-ATPase (SERCA). We describe the cloning, sequencing and characterization of a novel SERCA cDNA (3856 bp) obtained from crayfish axial abdominal muscle by reverse transcription/polymerase chain reaction (RT-PCR) followed by rapid amplification of cDNA ends (RACE). This complete sequence contains a 145 base pair (bp) noncoding region at the 5′ end, a 3006 bp open reading frame coding for 1002 amino acid residues with a molecular mass of 110 kDa and 705 bp of untranslated region at the 3′ end. This enzyme contains all the conserved domains found in ‘P’-type ATPases, and the hydropathy profile suggests a transmembrane organization typical of other SERCAs. It exhibits 80% amino acid identity with Drosophila melanogaster SERCA, 79% identity with Artemia franciscana SERCA, 72% identity with rabbit fast-twitch muscle neonatal isoform SERCA1b, 71% identity with slow-twitch muscle isoform SERCA2 and 67% identity with SERCA3. Sequence alignment revealed that regions anchoring the cytoplasmic domain in the membrane were highly conserved and that most differences were in the NH(2) terminus, the central loop region and the COOH terminus. Northern analysis of total RNA from crayfish tissues probed with the 460 bp fragment initially isolated showed four bands (7.6, 7.0, 5.8 and 4.5 kilobases) displaying tissue-specific expression. SERCA was most abundant in muscle (axial abdominal, cardiac and stomach), where it is involved in Ca(2+) resequestration during relaxation, and in eggs, where it may be implicated in early embryogenesis. The level of SERCA mRNA expression in axial abdominal muscle varied during the moulting cycle as determined by slot-blot analysis. SERCA expression was greatest during intermoult and decreased to approximately 50% of this level during pre- and postmoult. Patterns of gene expression for SERCA and other sarcomeric proteins during the crustacean moulting cycle may be regulated by ecdysteroids and/or mechanical stimulation.


1999 ◽  
Vol 81 (01) ◽  
pp. 81-86 ◽  
Author(s):  
Agnes Henschen-Edman ◽  
Ida Theodor ◽  
Brian Edwards ◽  
Hubert Pirkle

SummaryCrotalase, a fibrinogen-clotting enzyme isolated from the venom of Crotalus adamanteus, and its overlapping fragments were subjected to Edman degradation. The resulting amino acid sequence, VIGGDEC NINEHRFLVALYDYWSQLFLCGGTLINNEWVLTAAHCDRTHI LIYVGVHDRSVQFDKEQRRFPKEKYFFDCSNNFTKWDKDIM LIRLNKPVSYSEHIAPLSLPSSPPIVGSVCRAMGWGQTTSPQET LPDVPHCANINLLDYEVCRTAHPQFRLPATSRTLCAGVLEG GIDTCNRDSGGPLICNGQFQGIVFWGPDPCAQPDKPGLYTK VFDHLDWIQSIIAGEKTVNCP, is characteristic of a serine protein-ase. Comparison with thrombin, the physiological fibrinogen-clotting enzyme, showed that thrombin’s fibrinogen-recognition exosite (FRE) is poorly represented in crotalase. Hirudin, a FRE-dependent inhibitor, had no effect on crotalase. Spatial modeling of crotalase yielded a possible alternative fibrinogen-recognition site comprised of Arg 60F, Lys 85, Lys 87, and Arg 107 (underlined in the sequence above). Crotalase also lacks thrombin’s YPPW loop, as well as its functionally important ETW 146-148, and its heparin-binding site. The enzyme contains a single asparagine-linked glycosylation site, NFT, bearing neutral and amino sugars that account for 8.3% of the enzyme’s total molecular weight of 29,027. The calculated absorbance of crotalase at 280 nm, 1%, cm-1is 15.2.


1998 ◽  
pp. 30-33
Author(s):  
Jeffrey Griffith ◽  
Clare Sansom

1998 ◽  
Vol 330 (1) ◽  
pp. 321-327 ◽  
Author(s):  
Norihiro AZUMA ◽  
Hee-Chan SEO ◽  
Øystein LIE ◽  
Qiang FU ◽  
M. Robert GOULD ◽  
...  

Prosaposin is the precursor of four small glycoproteins, saposins A-D, that activate lysosomal sphingolipid hydrolysis. A full-length cDNA encoding prosaposin from chicken brain was isolated by PCR. The deduced amino acid sequence predicted that, similarly to human and other mammalian species studied, chicken prosaposin contains 518 residues, including four domains that correspond to saposins A-D. There was 59% identity and 76% similarity of human and chicken prosaposin amino acid sequences. The basic three-dimensional structures of these saposins is predicted to be similar on the basis of the conservation of six cysteine residues and an N-glycosylation site. Identity of amino acid sequences was higher among saposins A, B and D than in saposin C. The predicted amino acid sequence of saposin B matched exactly that of purified chicken saposin B protein. The chicken prosaposin gene was mapped to a single locus, PSAP, in chicken linkage group E11C10 and is closely linked to the ACTA2 locus. This confirms the homology between chicken and human prosaposins and defines a new conserved segment with human chromosome 10q21-q24.


Sign in / Sign up

Export Citation Format

Share Document