Abstract

The cydD gene of Escherichia coli encodes a protein which, together with the CydC protein, probably constitutes a heterodimeric, ABC-family membrane transporter, necessary for biosynthesis of the cytochrome bd quinol oxidase. Here, we demonstrate that a cydD mutant also fails to synthesise periplasmic c-type cytochrome(s), suggesting that the transporter exports haem or some other component involved in assembly of cytochromes that are found in, or exposed to, the periplasm. The CydDC system appears to be the first example of a transporter required for periplasmic cytochrome assembly processes requiring more than one type of haem. A mutant defective in trxB (adjacent to the cydDC operon, and encoding thioredoxin reductase) was unaffected in cytochrome c or bd assembly.

References

1
Poole
R.K.
(
1988
) In
Bacterial Energy Transduction
 
Bacterial cytochrome oxidases
.
Anthony
C.
, Ed) pp
231
291
Academic Press
,
London
.
2
Kahlow
M.A.
Zuberi
T.M.
Gennis
R.B.
Loehr
T.M.
(
1991
)
Identification of a ferryl intermediate of Escherichia coli cytochrome d terminal oxidase by resonance Raman spectroscopy
Biochemistry
 ,
30
,
11485
11489
.
3
Georgiou
C.D.
Fang
H.
Gennis
R.B.
(
1987
)
Identification of the cydC locus required for expression of the functional form of the cytochrome d terminal oxidase complex in Escherichia coli
J. Bacteriol.
 ,
169
,
2107
2112
.
4
Poole
R.K.
Williams
H.D.
Downie
J.A.
Gibson
F.
(
1989
)
Mutations affecting the cytochrome d-containing oxidase complex of Escherichia coli K12: Identification and mapping of a fourth locus, cydD
J. Gen. Microbiol.
 ,
135
,
1865
1874
.
5
Poole
R.K.
Hatch
L.
Cleeter
M.W.J.
Gibson
F.
Cox
G.B.
Wu
G.
(
1993
)
Cytochrome bd biosynthesis in Escherichia coli: the sequences of the cydC and cydD genes suggest that they encode the components of an ABC membrane transporter
Mol. Microbiol.
 ,
10
,
421
430
.
6
Fang
H.
Lin
R.-J.
Gennis
R.B.
(
1989
)
Location of heme axial ligands in the cytochrome d terminal oxidase complex of Escherichia coli determined by site-directed mutagenesis
J. Biol. Chem.
 ,
264
,
8026
8032
.
7
Ferguson
S.J.
Page
M.D.
(
1990
)
The functions and biosynthesis of the c-type cytochromes of bacterial respiratory chains with particular reference to autotrophs and the handling of C1 compounds
FEMS Microbiol. Rev.
 ,
87
,
227
234
.
8
Kranz
R.G.
(
1989
)
Isolation of mutants and genes involved in cytochromes c biosynthesis in Rhodobacter capsulatus
J. Bacteriol.
 ,
171
,
456
464
.
9
Ramseier
T.M.
Winteler
H.V.
Hennecke
H.
(
1991
)
Discovery and sequence analysis of bacterial genes involved in the biogenesis of c-type cytochromes
J. Biol. Chem.
 ,
266
,
7793
7803
.
10
Beckman
D.L.
Trawick
D.R.
Kranz
R.G.
(
1992
)
Bacterial cytochromes c biogenesis
Genes Dev.
 ,
6
,
268
283
.
11
Ritz
D.
Bott
M.
Hennecke
H.
(
1993
)
Formation of several bacterial c-type cytochromes requires a novel membrane-anchored protein that faces the periplasm
Mol. Microbiol.
 ,
9
,
729
740
.
12
Beckman
D.L.
Kranz
R.G.
(
1993
)
Cytochromes c biogenesis in a photosynthetic bacterium requires a periplasmic thioredoxin-like protein
 
2nd edition
,
90
, In
Proc. Natl. Acad. Sci. USA
 , pp
2179
2183
.
13
Loferer
H.
Bott
M.
Hennecke
H.
(
1993
)
Bradyrhizobium japonicum TlpA, a novel membrane-anchored thioredoxin-like protein involved in the biogenesis of cytochrome aa3 and development of symbiosis
EMBO J.
 ,
12
,
3373
3383
.
14
Willis
R.C.
Morris
R.G.
Cirakoglu
C.
Schellenberg
G.D.
Gerber
N.H.
Furlong
C.E.
(
1974
)
Preparation of the periplasmic binding proteins from Salmonella typhimurium and Escherichia coli
Arch. Biochem. Biophys.
 ,
161
,
64
75
.
15
Manoil
C.
Beckwith
J.
(
1984
)
A genetic approach to analysing membrane protein topology
Science
 ,
233
,
1403
1408
.
16
Poole
R.K.
Bashford
C.L.
(
1987
)
Spectra
In
Spectrophotometry and Spectrofluorimetry, A Practical Approach
 
Harris
D.A.
Bashford
C.L.
, Eds) pp
23
48
IRL Press
,
Oxford
.
17
Pope
N.R.
Cole
J.A.
(
1984
)
Pyruvate and ethanol as electron donors for nitrite reduction by Escherichia coli K12
J. Gen. Microbiol.
 ,
130
,
1279
1284
.
18
Poole
R.K.
(
1993
)
Analysis of cytochromes
In
Chemical Methods in Prokaryotic Systematics
 
Goodfellow
M.
O'Donnell
A.G.
, Eds) pp
311
344
John Wiley & Sons
,
Chichester
in press.
19
Kajie
S.
Anraku
Y.
(
1986
)
Purification of a hexaheme cytochrome c552 from Escherichia coli K12 and its properties as a nitrite reductase
Eur. J. Biochem.
 ,
154
,
457
463
.
20
Darwin
A.
Hussain
H.
Griffiths
L.
Grove
J.
Sambongi
Y.
Busby
S.
Cole
J.
(
1993
)
Regulation and sequence of the structural gene for cytochrome c552 from Escherichia coli: not a hexahaem but a 50-kDa tetrahaem nitrite reductase
Mol. Microbiol.
 ,
9
,
1255
1265
.
21
Markwell
M.A.K.
Haas
S.M.
Bieber
L.L.
Tolbert
N.E.
(
1978
)
A modification of the Lowry procedure to simplify protein determination in membrane and lipoprotein samples
Anal. Biochem.
 ,
87
,
206
210
.
22
Bebbington
K.J.
Williams
H.D.
(
1993
)
Investigation of the role of the cydD gene product in production of a functional cytochrome d oxidase in Escherichia coli
FEMS Microbiol. Lett.
 ,
112
,
19
24
.
23
Page
L.
Griffiths
L.
Cole
J.A.
(
1990
)
Different physiological roles of two independent pathways for nitrite reduction to ammonia by enteric bacteria
Arch. Microbiol.
 ,
154
,
349
354
.
24
Fu
H.A.
Iuchi
S.
Lin
E.C.C.
(
1991
)
The requirement of ArcA and Fnr for peak expression of the cyd operon in Escherichia coli under microaerophilic conditions
Mol. Gen. Genet.
 ,
226
,
209
213
.
25
Wood
P.M.
(
1983
)
Why do c-type cytochromes exist?
FEBS Lett.
 ,
164
,
223
226
.
26
Bardwell
J.C.A.
McGovern
K.
Beckwith
J.
(
1991
)
Identification of a protein required for disulfide bond formation in vivo
Cell
 ,
67
,
581
589
.
27
Bragg
P.D.
Hackett
N.R.
(
1983
)
Cytochromes of the trimethylamine N-oxide anaerobic respiratory pathway of Escherichia coli
Biochim. Biophys. Acta
 ,
725
,
168
177
.
28
Page
M.D.
Ferguson
S.J.
(
1990
)
Apo forms of cytochrome c550 and cytochrome cd1 are translocated to the periplasm of Paracoccus denitrificans in the absence of haem incorporation caused by either mutation or inhibition of haem synthesis
Mol. Microbiol.
 ,
4
,
1181
1192
.
29
von Wachenfeldt
C.
Hederstedt
L.
(
1990
)
Bacillus subtilis holo-cytochrome c-550 can be synthesised in aerobic Escherichia coli
FEBS Lett.
 ,
270
,
147
151
.
30
Adler
S.
Modrich
P.
(
1983
)
T7-induced DNA polymerase. Requirement for thioredoxin sulfhydryl groups
J. Biol. Chem.
 ,
258
,
6956
6962
.