Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.6.1.44 (AGT)
 770 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A mutation of the psbA gene was identified in photoautotrophic potato (Solanum tuberosum L. cv Superior x U.S. Department of Agriculture line 66-142) cells selected for resistance to 6-chloro-N-ethyl-N'-(1-methylethyl)-1,3,5-triazine-2,4-diamine (atrazine). Photoaffinity labeling with 6-azido-N-ethyl-N'-(1-methylethyl)-1,3,5-triazine-2,4-diamine detected a thylakoid membrane protein with a M(r) of 32,000 in susceptible, but not in resistant, cells. This protein was identified as the secondary quinone acceptor of photosystem II (QB) protein. Atrazine resistance in selected cells was attributable to a mutation from AGT (serine) to ACT (threonine) in codon 264 of the psbA gene that encodes the QB protein. Although the mutant cells exhibited extreme levels of resistance to atrazine, no concomitant reductions in photosynthetic electron transport or cell growth rates compared to the unselected cells were detected. This is in contrast with the losses in productivity observed in atrazine-resistant mutants that contain a glycine-264 alteration.
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PMID:A serine-to-threonine substitution in the triazine herbicide-binding protein in potato cells results in atrazine resistance without impairing productivity. 802 41

Atrazine-resistant weeds are well known, and the resistance is primarily caused by a point mutation in the psbA chloroplast gene encoding the photosystem II D1 protein. Heteroplasmy, the presence of different types of chloroplasts in an individual plant, is also very common. Thus, atrazine-resistant weeds may also partly possess the atrazine-binding sequence and vice versa. The region of the psbA gene containing the mutation was sequenced from atrazine-resistant and atrazine-sensitive Chenopodium album and Senecio vulgaris plants. In atrazine-sensitive C. album plants, the expected AGT triplet was found. The atrazine-resistant plants contained the expected base substitution (AGT to GGT); however, in addition the AGT triplet was found. The atrazine-resistant S. vulgaris plants contained the expected GGT sequence, whereas the atrazine-sensitive plants contained both the AGT and GGT sequences. This clearly indicates that in addition to Gly264 also Ser264 is present in atrazine-resistant plants, and vice versa in atrazine-sensitive plants, indicating heteroplasmy in these weeds.
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PMID:Heteroplasmy and atrazine resistance in Chenopodium album and Senecio vulgaris. 2746 50