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Endogenous polypeptide-chain length and partial sequence of aspartate transcarbamoylase from wheat, characterised by immunochemical and cDNA methods

Bartlett, T.J., Aibangbee, A., Bruce, Ian J., Donovan, P.J., Yon, R.J. (1994) Endogenous polypeptide-chain length and partial sequence of aspartate transcarbamoylase from wheat, characterised by immunochemical and cDNA methods. Biochimica et Biophysica Acta (BBA)/Protein Structure and Molecular, 1207 (2). pp. 187-193. ISSN 0167-4838. (doi:10.1016/0167-4838(94)00068-9) (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided)

The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided. (Contact us about this Publication)
Official URL
http://dx.doi.org/10.1016/0167-4838(94)00068-9

Abstract

Aspartate transcarbamoylase (ATCase) is purified from wheat germ as a monofunctional trimer of 36 kDa chains. The possibility that this may be a proteolytic fragment of a large endogenous complex in which ATCase is covalently fused to other pyrimidine-pathway enzymes (such as exists in animals or fungi) was tested. Examination of a rabbit antiserum raised against the purified enzyme confirmed the presence of anti-(wheat ATCase) antibodies by several independent methods. Extracts of wheat seedlings prepared under non-proteolysing conditions were challenged by the antiserum, and in some cases by purified anti-(36 kDa ATCase) antibodies, using immunoblotting techniques. The 36 kDa species was the dominant immunopositive polypeptide. However, the extract also contained small amounts of two larger (45 and 55 kDa) immunopositive polypeptides, as well as traces of polypeptides smaller than 36 kDa, which were assumed to be minor proteolytic products. Neither of the 45 or 55 kDa polypeptides is large enough to also incorporate a carbamoyl phosphate synthetase or dihydroorotase of the sizes found in other organisms. They may be targeted precursors of ATCase with intact leader sequences. A screen of a wheat cDNA expression library by the anti-(ATCase) serum yielded a single positive clone which was shown, by DNA sequencing, to be a concatemer of two cDNAs, one of which encoded a partial ATCase. Northern analysis using this clone as probe identified two transcripts of about 1.3 and 1.0 kbp, but showed no evidence of a transcript of 2 kbp or greater which would be required to encode a bifunctional polypeptide. These results confirm that wheat ATCase is not translationally fused to dihydroorotase or carbamoylphosphate synthetase, as it is in animals and fungi. The deduced amino-acid sequence of the partial wheat ATCase is compared with the catalytic chain of the ATCase from Escherichia coli and with other ATCases.

Item Type: Article
DOI/Identification number: 10.1016/0167-4838(94)00068-9
Uncontrolled keywords: aspartate carbamoyltransferase, allosterism; amino acid sequence; article; dna sequence; enzyme purification; immunochemistry; molecular cloning; nonhuman; priority journal; pyrimidine synthesis; wheat, Amino Acid Sequence; Animal; Aspartate Carbamoyltransferase; Bacillus subtilis; Blotting, Northern; Comparative Study; Deoxyribonuclease EcoRI; Dictyostelium; Drosophila melanogaster; Escherichia coli; Immunoblotting; Molecular Sequence Data; Saccharomyces cerevisiae; Sequence Alignment; Sequence Analysis, DNA; Support, Non-U.S. Gov't; Triticum, Animalia; Escherichia coli; Fungi; Oryctolagus cuniculus; Triticum aestivum
Subjects: Q Science > QK Botany
Divisions: Faculties > Sciences > School of Physical Sciences
Faculties > Sciences > School of Physical Sciences > Functional Materials Group
Depositing User: I. Bruce
Date Deposited: 30 Jan 2019 16:37 UTC
Last Modified: 30 May 2019 08:50 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/71987 (The current URI for this page, for reference purposes)
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