The Control of Homoserine-O-transsuccinylase in a Methionine-requiring Mutant of the Blue-green Alga Anacystis nidulans

Delaney, Stephen F.; Dickson, Andrew G.; Carr, N. G.

doi:10.1099/00221287-79-1-89

Cited by 24 publications

(12 citation statements)

References 8 publications

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“…The differential reduction of the sulfur-containing intermediates APS by plants and PAPS by bacteria (Goldschmidt et al, 1975) is the major feature discriminating photosynthet ic and non-photosynthetic su 1 fate reduction pathways . Others have analysed the mechanism of the cysteine synthetase complex in detail Hulanicka et aL., 1979;Kredi ch, 1971;Kred i ch and Tomk ins, 1966), as well as the three step sequence in the conversion of cysteine to methionine (Delaney et al, 1973;Giovanelli et al, 1973;Rowbury and Woods~ 1964a,b Bearing in' mind the importance of sulfur-containing amino acids in the maintenance af protein structure and function, a relatively constant proportion of sulfur-containing amino acids may be found in bulk protein.…”

Section: Discussionmentioning

confidence: 99%

Assimilatory sulfur metabolism in marine microorganisms

Cuhel¹

1980

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Section: Discussionmentioning

confidence: 99%

Assimilatory sulfur metabolism in marine microorganisms

Cuhel¹

1980

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“…This has resulted in the suggestion that the inability to control enzyme activity at the transcriptional level is a characteristic feature of obligate autotrophic physiology (Carr, 1973). In particular, the presence or absence of organic compounds has little effect on the specific activities of enzymes of intermediary metabolism (Pearce & Carr, 1967; or amino acid biosynthesis (Hood & Carr, 1971, 1972Weber & Bock, 1968 ;Delaney et al, 1973). Furthermore, even facultatively phototrophic cyanobacteria such as Aphanocapsa strain 67 14 and Chlorogloea fritschii showed only minor alteration in the specific activities of enzymes involved in sugar and carboxylic acid metabolism (Joset-Espardellier et al, 1978).…”

Section: Introductionmentioning

confidence: 99%

Enzymes of the Calvin Cycle and Intermediary Metabolism in the Cyanobacterium Anacystis nidulans Grown in Chemostat Culture

Karagouni

Slater

1979

Journal of General Microbiology

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The cyanobacterium Anacystis nidulans grown in light-limited and C0,-limited chemostat cultures showed varying rates of CO, fixation with peaks at dilution rates of 0.10 to 0.12 h-l. The specific activities of a number of enzymes of the reductive and oxidative pentose phosphate and glycolytic pathways and the tricarboxylic acid and glyoxylate cycles varied significantly as a function of the growth environment (substrate limitation) and organism growth rate. Ribulose-l,5-bisphosphate carboxylase varied 15-fold under C0,-limited conditions but did not change under light-limited conditions. With the exception of phosphoribulokinase, all enzymes which showed a change in specific activity increased with decreasing dilution rate. The specific activities of glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, hexokinase, ri bulose-1,5-bisphosphate carboxylase and malate dehydrogenase were significantly higher in organisms grown under C0,-limited conditions than under light-limited conditions. Fructose-1,6-bisphosphate aldolase and phosphoribulokinase specific activities were similar at all growth rates and under both limitations. Isocitrate lyase was the only enzyme examined which showed higher specific activities under light-limited conditions. Thus Anacystis nidulans can selectively express different enzymes, possibly by transcriptional control.

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“…This has now been accomplished with strains requiring tryptophan (Ingram et al I 972), methionine (Delaney et al 1973) and phenylalanine (this work); however, the first mentioned remains the sole example of enzyme repression in cyanophytes. The absence of transcriptional-level control of enzymes in the blue-green algae, as in other photoautotrophic organisms, has been discussed by Carr (1973) as a possible basis for some of their metabolic peculiarities, such as their general failure to respond with increased growth rates to exogenously supplied nutrilites such as hexoses and amino acids.…”

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confidence: 99%