Identification of NdhL and Ssl1690 (NdhO) in NDH-1L, and NDH-1M complexes of Synechocystis sp PCC 6803

: Battchikova N, Zhang PP, Rudd S, Ogawa T, Aro EM

Publisher: AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC

: 2005

: Journal of Biological Chemistry

: JOURNAL OF BIOLOGICAL CHEMISTRY

: J BIOL CHEM

: 280

: 4

: 2587

: 2595

: 9

: 0021-9258

DOI: https://doi.org/10.1074/jbc.M410914200

The subunit compositions of two types of NAD(P)H dehydrogenase complexes of Synechocystis sp. PCC 6803, NDH-1L and NDH-1M, were studied by two-dimensional blue-native/SDS-PAGE followed by electrospray tandem mass spectrometry. Fifteen proteins were observed in NDH-1L including hydrophilic subunits (NdhH, -K, -I, -J, -M, and -N) and hydrophobic subunits (NdhA, -B, -E, -G, -D1, and -F1). In addition, NdhL and a novel subunit, SsI1690 (designated NdhO), were shown to be components of this complex. All subunits mentioned above were present in the NDH-1M complex except NdhD1 and NdhF1. NdhL and SsI1690 (NdhO) were homologous to hypothetical proteins encoded by genomic DNA in higher plants, suggesting that chloroplast NDH-1 complexes contain related subunits. Diagnostic sequence motifs were found for both NdhL and NdhO homologous proteins. Analysis of ndhL deletion mutant (W revealed the presence of assembled NDH-1L and NDH-1M complexes, but these complexes appear to be functionally impaired in the absence of NdhL. Both NDH-1 complexes were absent in the ndhB deletion mutant (M55).