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N‐terminal sequencing of low‐molecular‐mass components in cyanobacterial photosystem II core complex Two components correspond to unidentified open reading frames of plant chloroplast DNA
Author(s) -
Ikeuchi Masahiko,
Koike Hiroyuki,
Inoue Yorinao
Publication year - 1989
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(89)80954-8
Subject(s) - open reading frame , chloroplast , chloroplast dna , biology , dna , molecular mass , genetics , gene , microbiology and biotechnology , peptide sequence , biochemistry , enzyme
We recently reported the presence of several low‐molecular‐mass protein components in the PS II O 2 ‐evolving core complex from the thermophilic cyanobacterium, Synechococcus vulcanus [(1989) FEBS Lett. 244, 391–396]. Here we have characterized the three components (4.1, 4.7, 5 kDa) of the same cyanobacterial core complex by N‐terminal sequencing. There were two components in the 4.7 kDa region, both having a blocked N‐terminus. One has a sequence highly homologous to open reading frame 34 of plant chloroplast DNA (tentatively designated psb M), while the other has a sequence partially homologous to open reading frame 43 of chloroplast DNA (designated psb N), although neither of the two gene products has yet been confirmed in chloroplasts. The cyanobacterial 4.1 kDa protein partially corresponds to the 4.1 kDa nuclear‐encoded core component of higher plant PS II. The cyanobacterial 5 kDa component, however, shows a sequence that is unrelated to any other known proteins.