PMID- 18761666
OWN - NLM
STAT- MEDLINE
DCOM- 20081217
LR  - 20081031
IS  - 1462-2920 (Electronic)
IS  - 1462-2912 (Linking)
VI  - 10
IP  - 11
DP  - 2008 Nov
TI  - Evolution of an octahaem cytochrome c protein family that is key to aerobic and 
      anaerobic ammonia oxidation by bacteria.
PG  - 3150-63
LID - 10.1111/j.1462-2920.2008.01733.x [doi]
AB  - The biogeochemical nitrogen cycle is mediated by many groups of microorganisms 
      that harbour octahaem cytochromes c (OCC). In this study molecular evolutionary 
      analyses and the conservation of predicted functional residues and secondary 
      structure were employed to investigate the descent of OCC proteins related to 
      hydroxylamine oxidoreductase (HAO) and hydrazine oxidoreductase (HZO) from 
      pentahaem cytochrome c nitrite reductase (NrfA). An octahaem cytochrome cnitrite 
      reductase (ONR) was shown to be a possible intermediate in the process. Analysis 
      of genomic neighbourhoods of OCC protein-encoding genes revealed adjacent 
      conserved genes whose products, together with HAO, provide a path of electron 
      transfer to quinone and constitute a functional catabolic module. The latter has 
      evolved more than once under a variety of functional pressures on the catabolic 
      lifestyles of their bacterial hosts. Structurally, the archetypical long helices 
      in the large C-terminal domain of the proteins as well as the distal axial 
      ligands to most haems were highly conserved in NrfA and all descendents. Residues 
      known to be involved in the nitrite reductase activity of NrfA including the 
      'CxxCK' motif at the catalytic haem, the substrate and Ca binding sites, and the 
      nitrite and ammonium channels were conserved in the eight representatives of ONR. 
      In the latter, a unique cysteine has been inserted above the active site. The 64 
      other OCC proteins differed from ONR by the absence of the 'CxxCK' motif, the 
      channel residues and most of the Ca-binding residues and the conserved presence 
      of an 'Asp-His' pair inserted above the active site as well as the tyrosine that 
      forms an intersubunit cross-link to the catalytic haem of HAO. Our proposed 
      scenario of evolution of OCC proteins in the HAO family from NrfA is supported by 
      (i) homology based on sequence and structure, (ii) its wide distribution among 
      bacterial taxa, (iii) the dedicated interaction with specific proteins, and it is 
      (iv) congruent with geological history.
FAU - Klotz, Martin G
AU  - Klotz MG
AD  - Department of Biology, Evolutionary and Genomic Microbiology Laboratory, 
      University of Louisville, KY, USA. martin.klotz@louisville.edu
FAU - Schmid, Markus C
AU  - Schmid MC
FAU - Strous, Marc
AU  - Strous M
FAU - op den Camp, Huub J M
AU  - op den Camp HJ
FAU - Jetten, Mike S M
AU  - Jetten MS
FAU - Hooper, Alan B
AU  - Hooper AB
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, Non-P.H.S.
DEP - 20080828
PL  - England
TA  - Environ Microbiol
JT  - Environmental microbiology
JID - 100883692
RN  - 0 (Bacterial Proteins)
RN  - 0 (Cytochrome c Group)
RN  - 7664-41-7 (Ammonia)
RN  - 9035-44-3 (cytochrome c(3))
SB  - IM
MH  - Amino Acid Motifs
MH  - Amino Acid Sequence
MH  - Ammonia
MH  - Bacteria, Aerobic/*enzymology/genetics
MH  - Bacteria, Anaerobic/*enzymology/genetics
MH  - Bacterial Proteins/*genetics
MH  - Binding Sites
MH  - Conserved Sequence
MH  - Cytochrome c Group/chemistry/*genetics
MH  - *Evolution, Molecular
MH  - Models, Biological
MH  - Phylogeny
MH  - Protein Structure, Secondary
MH  - Sequence Alignment
MH  - Sequence Homology, Amino Acid
EDAT- 2008/09/03 09:00
MHDA- 2008/12/18 09:00
CRDT- 2008/09/03 09:00
PHST- 2008/09/03 09:00 [pubmed]
PHST- 2008/12/18 09:00 [medline]
PHST- 2008/09/03 09:00 [entrez]
AID - EMI1733 [pii]
AID - 10.1111/j.1462-2920.2008.01733.x [doi]
PST - ppublish
SO  - Environ Microbiol. 2008 Nov;10(11):3150-63. doi: 
      10.1111/j.1462-2920.2008.01733.x. Epub 2008 Aug 28.