biostudies-literatureUnknown283(44)Dines MThe enormous macromolecular phycobilisome antenna complex (>4 MDa) in cyanobacteria and red algae undergoes controlled degradation during certain forms of nutrient starvation. The NblA protein (approximately 6 kDa) has been identified as an essential component in this process. We have used structural, biochemical, and genetic methods to obtain molecular details on the mode of action of the NblA protein. We have determined the three-dimensional structure of the NblA protein from both the thermophilic cyanobacterium Thermosynechococcus vulcanus and the mesophilic cyanobacterium Synechococcus elongatus sp. PCC 7942. The NblA monomer has a helix-loop-helix motif which dimerizes into an open, four-helical bundle, identical to the previously determined NblA structure from Anabaena. Previous studThe Journal of biological chemistry30330-40https://www.ebi.ac.uk/biostudies/studies/S-EPMC2662085biostudies-literatureStructural, functional, and mutational analysis of the NblA protein provides insight into possible modes of interaction with the phycobilisome.PMC2662085Sendersky ESchwarz RDines MAdir NDavid LfalseStructural, functional, and mutational analysis of the NblA protein provides insight into possible modes of interaction with the phycobilisome.The enormous macromolecular phycobilisome antenna complex (>4 MDa) in cyanobacteria and red algae undergoes controlled degradation during certain forms of nutrient starvation. The NblA protein (approximately 6 kDa) has been identified as an essential component in this process. We have used structural, biochemical, and genetic methods to obtain molecular details on the mode of action of the NblA protein. We have determined the three-dimensional structure of the NblA protein from both the thermophilic cyanobacterium Thermosynechococcus vulcanus and the mesophilic cyanobacterium Synechococcus elongatus sp. PCC 7942. The NblA monomer has a helix-loop-helix motif which dimerizes into an open, four-helical bundle, identical to the previously determined NblA structure from Anabaena. Previous stud2008-01-01T00:00:00Z2008 Oct2026-04-29T03:33:53.952Z2019-03-27T00:21:27ZS-EPMC26620851871890710.1074/jbc.m80424120010.1074/jbc.M804241200