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DNA polymerase activity of tomato fruit chromoplasts
Author(s) -
Serra Esteban C.,
Carrillo Nestor
Publication year - 1990
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(90)81449-x
Subject(s) - chromoplast , plastid , ripening , biology , chloroplast , biochemistry , dna , rna polymerase , enzyme , polymerase , transcription (linguistics) , chloroplast dna , dna polymerase , microbiology and biotechnology , rna , botany , gene , linguistics , philosophy
DNA polymerase activity was measured in chromoplasts of ripening tomato fruits. Plastids isolated from young leaves or mature red fruits showed similar DNA polymerase activities. The same enzyme species was present in either chloroplasts or chromoplasts as judged by PH and temperature profiles, sensitivities towards different inhibitors and relative molecular mass ( M 1 88 kDa). The activities analyzed showed the typical behaviour of plastid‐type polymerases. The results presented here suggest that chromoplasts maintain their DNA synthesis potential in fruit tissue at chloroplast levels. Consequently, the sharp decrease of the plastid chromosome transcription observed at the onset of fruit ripening could not be due to limitations in the availability of template molecules. Other mechanisms must be involved in the inhibition of chromoplast RNA synthesis.