Autotrophic CO2 fixation by Chloroflexus aurantiacus:: Study of glyoxylate formation and assimilation via the 3-hydroxypropionate cycle

被引:68
作者
Herter, S
Farfsing, J
Gad'on, N
Rieder, C
Eisenreich, W
Bacher, A
Fuchs, G
机构
[1] Univ Freiburg, Inst Biol 2, D-79104 Freiburg, Germany
[2] Tech Univ Munich, D-8000 Munich, Germany
关键词
D O I
10.1128/JB.183.14.4305-4316.2001
中图分类号
Q93 [微生物学];
学科分类号
071005 ; 100705 ;
摘要
In the facultative autotrophic organism Chloroflexus aurantiacus, a phototrophic green nonsulfur bacterium, the Calvin cycle does not appear to be operative in autotrophic carbon assimilation. An alternative cyclic pathway, the 3-hydroxypropionate cycle, has been proposed. In this pathway, acetyl coenzyme A (acetyl-CoA) is assumed to be converted to malate, and two CO2 molecules are thereby fixed. Malyl-CoA is supposed to be cleaved to acetyl-CoA, the starting molecule, and glyoxylate, the carbon fixation product. Malyl-CoA cleavage is shown here to be catalyzed by malyl-CoA lyase; this enzyme activity is induced severalfold in autotrophically grown cells. Malate is converted to malyl-CoA via an inducible CoA transferase with succinyl-CoA as a CoA donor. Some enzyme activities involved in the conversion of malonyl-CoA via 3-hydroxypropionate to propionyl-CoA are also induced under autotrophic growth conditions. So far, no clue as to the first step in glyoxylate assimilation has been obtained. One possibility for the assimilation of glyoxylate involves the conversion of glyoxylate to glycine and the subsequent assimilation of glycine. However, such a pathway does not occur, as shown by labeling of whole cells with [1,2-C-13(2)]glycine, Glycine carbon was incorporated only into glycine, serine, and compounds that contained C-1 units derived therefrom and not into other cell compounds.
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页码:4305 / 4316
页数:12
相关论文
共 42 条
[1]  
Bacher A, 1998, FEMS MICROBIOL REV, V22, P567
[2]  
BERGMEYER HU, 1970, METHODEN ENZYMETISCH, V2
[3]  
BRADFORD MM, 1976, ANAL BIOCHEM, V72, P248, DOI 10.1016/0003-2697(76)90527-3
[4]   Carboxylase genes of Sulfolobus metallicus [J].
Burton, NP ;
Williams, TD ;
Norris, PR .
ARCHIVES OF MICROBIOLOGY, 1999, 172 (06) :349-353
[5]   THERMOPHILIC BLUE-GREEN ALGAE AND THERMAL ENVIRONMENT [J].
CASTENHOLZ, RW .
BACTERIOLOGICAL REVIEWS, 1969, 33 (04) :476-+
[6]  
CHANG YY, 1993, J BIOL CHEM, V268, P3911
[7]   SYNTHESIS AND HYDROLYSIS OF MALYL-COENZYME-A BY PSEUDOMONAS AM1 - APPARENT MALATE SYNTHASE ACTIVITY [J].
COX, RB ;
QUAYLE, JR .
JOURNAL OF GENERAL MICROBIOLOGY, 1976, 95 (JUL) :121-133
[8]  
Dawson R.M. C., 2002, DATA BIOCH RES
[9]  
DUNCAN RJS, 1986, ARCH BIOCHEM BIOPHYS, V201, P128
[10]  
EGGERER H, 1964, BIOCHEM Z, V339, P436