Chlorobaculum tepidum regulates chlorosome structure and function in response to temperature and electron donor availability.
Green sulfur bacteria (GSB) rely on the chlorosome, a light-harvesting apparatus comprised almost entirely of self-organizing arrays of bacteriochlorophyll (BChl) molecules, to harvest light energy and pass it to the reaction center. In Chlorobaculum tepidum, over 97% of the total BChl is made up of a mixture of four BChl c homologs in the chlorosome that differ in the number and identity of alkyl side chains attached to the chlorin ring. C. tepidum has been reported to vary the distribution of BChl c homologs with growth light intensity, with the highest degree of BChl c alkylation observed under low-light conditions. Here, we provide evidence that this functional response at the level of the chlorosome can be induced not only by light intensity, but also by temperature and a mutation that prevents phototrophic thiosulfate oxidation. Furthermore, we show that in conjunction with these functional adjustments, the fraction of cellular volume occupied by chlorosomes was altered in response to environmental conditions that perturb the balance between energy absorbed by the light-harvesting apparatus and energy utilized by downstream metabolic reactions.
Morgan-Kiss
Rachael M
RM
Department of Microbiology, Miami University, Oxford, OH, 45045, USA.
Chan
Leong-Keat
LK
Modla
Shannon
S
Weber
Timothy S
TS
Warner
Mark
M
Czymmek
Kirk J
KJ
Hanson
Thomas E
TE
D000478:Alkylation / Q000528:radiation effects; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D001429:Bacteriochlorophylls / Q000737:chemistry* / Q000378:metabolism*; D019414:Chlorobi / Q000254:growth & development / Q000378:metabolism* / Q000528:radiation effects / Q000648:ultrastructure; D002851:Chromatography, High Pressure Liquid; D004583:Electrons; D008027:Light; D008954:Models, Biological; D017386:Sequence Homology, Amino Acid; D013050:Spectrometry, Fluorescence; D013696:Temperature
D001426:Bacterial Proteins; D001429:Bacteriochlorophylls; C002084:bacteriochlorophyll c
Science. 2007 Jul 27;317(5837):523-6
17656724
J Bacteriol. 1995 May;177(9):2583-8
7730296
Proc Natl Acad Sci U S A. 2002 Jul 9;99(14):9509-14
12093901
J Bacteriol. 2007 Sep;189(17):6176-84
17586634
Eur J Biochem. 2000 Jan;267(2):450-6
10632714
Biochemistry. 1990 May 8;29(18):4340-8
2350541
Photosynth Res. 1995 Jul;45(1):21-30
24301376
Biochim Biophys Acta. 1960 Jul 15;41:478-84
13833770
Appl Environ Microbiol. 2001 Jun;67(6):2538-44
11375161
Photosynth Res. 2005 Nov;86(1-2):145-54
16172934
Photosynth Res. 2005 Nov;86(1-2):123-30
16172931
J Cell Biol. 1963 Apr;17:208-12
13986422
Proc Natl Acad Sci U S A. 1966 Apr;55(4):928-34
5219700
Annu Rev Microbiol. 1974;28(0):167-87
4372937
J Bacteriol. 1997 Aug;179(15):4859-67
9244275
Arch Microbiol. 2004 Oct;182(4):265-76
15340781
Proc Natl Acad Sci U S A. 2001 Apr 10;98(8):4397-402
11287671
FEMS Microbiol Lett. 1998 Jul 15;164(2):353-61
9682485
Proc Natl Acad Sci U S A. 2007 Jan 16;104(3):790-5
17215361
Biophys J. 2003 Oct;85(4):2560-5
14507718
Microbiology (Reading). 2008 Mar;154(Pt 3):818-829
18310028
Biochim Biophys Acta. 2002 May 20;1597(1):123-32
12009411
Arch Microbiol. 1999 Aug;172(2):116-24
10415173
Appl Environ Microbiol. 1999 Jan;65(1):301-6
9872796
Photosynth Res. 1990 Oct;26(1):39-48
24420408
Photosynth Res. 2003;78(2):93-117
16245042