Affiliation:
1. Department of Microbiology, The University of Mississippi Medical Center, Jackson, Mississippi
2. Biology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee
Abstract
Johnson, Emmett
J. (University of Mississippi Medical Center, Jackson),
and Harry D. Peck, Jr
. Coupling of phosphorylation and carbon dioxide fixation in extracts of
Thiobacillus thioparus
. J. Bacteriol.
89:
1041–1050. 1965.—A cell-free system from
Thiobacillus thioparus
which fixes large quantities of C
14
O
2
in the presence of ribose-5-phosphate, adenosine triphosphate (ATP), and Mg
++
has been described. The specific activity (0.041 μmole of ribulose-1,5-diphosphate min
−1
mg
−1
protein) of the CO
2
-fixing system approaches that of green plants, and is further evidence for the importance of the role of carboxydismutase in the thiobacilli. In addition to ATP, adenosine diphosphate (ADP) and other nucleoside triphosphates served with varying degrees of effectiveness for the fixation of C
14
O
2
. The ATP requirement for CO
2
fixation was partially replaced under aerobic conditions by a combination of SO
3
=
, PO
4
≡
, and adenosine monophosphate (AMP). Phosphorylation and CO
2
fixation were separated in time by first incubating SO
3
=
and AMP aerobically, and then anaerobically introducing C
14
O
3
=
and ribose-5-phosphate into the reaction mixture. During the first incubation, P
32
O
4
≡
was esterified into nucleotides, mainly ADP, and in the second incubation C
14
O
2
was fixed, with the concomitant utilization of almost equal amounts of the esterified phosphate. These data provide the first in vitro evidence for the mechanism of the coupling of CO
2
fixation and phosphorylation in
T. thioparus
. The fixation of C
14
O
2
was shown to be almost completely inhibited by AMP. This inhibition was not due to the conversion of ATP to ADP by adenylic kinase, or to the binding of magnesium by the nucleotide. The inhibition was specific for AMP, since other mononucleotides, adenosine, and adenine did not inhibit. The AMP regulation of CO
2
fixation may represent a basic control mechanism in autotrophic metabolism.
Publisher
American Society for Microbiology
Subject
Molecular Biology,Microbiology
Reference28 articles.
1. Existence, isolement et propridt 6s physico-chimiques d'un cytochromec de Thiobacillus denitrificans;AUJBERT J. P.;Compt. Rend.,1958
2. The role of phosphate in C02 assimilation of Thiobacilli. Phosphorus Metab., Symp., Baltimore, Johns Hopkins Univ;BAALSRUD K.;McCollum-Pratt Inst. Contrib.,1952
3. The path of carbon in photosynthesis. XXI. The cyclic regeneration of carbon dioxide acceptors;BASSHAM J. A.;J. Am. Chem. Soc.,1954
4. The occurrence of cytochrome and coenzyme Q in Thiobacillus thiooxidans;W. W.;Biochemistry,1963
5. ELSDEN S. R. 1962. Photosynthesis and lithotrophic carbon dioxide fixation p. 1-40. In I. C. Gunsalus and R. Y. Stanier [ed.] The bacteria vol. 3. Academic Press Inc. New York.
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