Abstract:
:The light-harvesting phycobilisome in cyanobacteria and red algae requires the lyase-catalyzed chromophorylation of phycobiliproteins. There are three functionally distinct lyase families known. The heterodimeric E/F type is specific for attaching bilins covalently to α-subunits of phycocyanins and phycoerythrins. Unlike other lyases, the lyase also has chromophore-detaching activity. A subclass of the E/F-type lyases is, furthermore, capable of chemically modifying the chromophore. Although these enzymes were characterized >25 y ago, their structures remained unknown. We determined the crystal structure of the heterodimer of CpcE/F from Nostoc sp. PCC7120 at 1.89-Å resolution. Both subunits are twisted, crescent-shaped α-solenoid structures. CpcE has 15 and CpcF 10 helices. The inner (concave) layer of CpcE (helices h2, 4, 6, 8, 10, 12, and 14) and the outer (convex) layer of CpcF (h16, 18, 20, 22, and 24) form a cavity into which the phycocyanobilin chromophore can be modeled. This location of the chromophore is supported by mutations at the interface between the subunits and within the cavity. The structure of a structurally related, isomerizing lyase, PecE/F, that converts phycocyanobilin into phycoviolobilin, was modeled using the CpcE/F structure as template. A H87C88 motif critical for the isomerase activity of PecE/F is located at the loop between h20 and h21, supporting the proposal that the nucleophilic addition of Cys-88 to C10 of phycocyanobilin induces the isomerization of phycocyanobilin into phycoviolobilin. Also, the structure of NblB, involved in phycobilisome degradation could be modeled using CpcE as template. Combined with CpcF, NblB shows a low chromophore-detaching activity.
journal_name
Proc Natl Acad Sci U S Aauthors
Zhao C,Höppner A,Xu QZ,Gärtner W,Scheer H,Zhou M,Zhao KHdoi
10.1073/pnas.1715495114subject
Has Abstractpub_date
2017-12-12 00:00:00pages
13170-13175issue
50eissn
0027-8424issn
1091-6490pii
1715495114journal_volume
114pub_type
杂志文章abstract::The mitochondria are the major source of chronic oxidative stress, which has been implicated in the aging process. Along with other cellular changes, aged cells accumulate mutations in both their nuclear and mitochondrial genomes, and they contain increased amounts of oxidatively damaged mutagenic bases such as 7,8-di...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1932854100
更新日期:2003-09-16 00:00:00
abstract::Tumor-derived adhesion factor (TAF) was previously identified as a cell adhesion molecule secreted by human bladder carcinoma cell line EJ-1. To elucidate the physiological function of TAF, we examined its distribution in human normal and tumor tissues. Immunochemical staining with an anti-TAF monoclonal antibody show...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.93.16.8384
更新日期:1996-08-06 00:00:00
abstract::Daytime sleepiness impairs cognitive ability, but recent evidence suggests it is also an important driver of human motivation and behavior. We aimed to investigate the relationship between sleepiness and a behavior strongly associated with better health: social activity. We additionally aimed to investigate whether a ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.2004535117
更新日期:2020-09-01 00:00:00
abstract::Although malignant astrocytomas are a leading cause of cancer-related death in children, rational therapeutic strategies are lacking. We previously identified activating mutations of v-raf murine sarcoma viral oncogene homolog B1 (BRAF) (BRAF(T1799A) encoding BRAF(V600E)) in association with homozygous cyclin-dependen...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1117255109
更新日期:2012-05-29 00:00:00
abstract::In vitro translation of Rous sarcoma virus (RSV) virion RNA in the messenger-dependent reticulocyte lysate system yielded polypeptides that were not synthesized by translation of RNA from a transformation-defective deletion mutant of RSV. These RSV-specific products migrated on sodium dodecyl sulfate/polyacrylamide ge...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.74.8.3302
更新日期:1977-08-01 00:00:00
abstract::It is known from a variety of experimental systems that the ability of tumor cells to grow locally and metastasize can be affected by the presence of adjacent normal tissues and cells, particularly mesenchymally derived stromal cells such as fibroblasts. However, the comparative influence of such normal cell-tumor cel...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.88.14.6028
更新日期:1991-07-15 00:00:00
abstract::Costimulation is required for optimal T cell activation, yet it is unclear whether poxviruses dedicatedly subvert costimulation during infection. Here, we report that the secreted M2 protein encoded by cowpox virus (CPXV) specifically interacts with human and murine B7.1 (CD80) and B7.2 (CD86). We also show that M2 co...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1909414116
更新日期:2019-10-15 00:00:00
abstract::A cardinal symptom of major depressive disorder (MDD) is the disruption of circadian patterns. However, to date, there is no direct evidence of circadian clock dysregulation in the brains of patients who have MDD. Circadian rhythmicity of gene expression has been observed in animals and peripheral human tissues, but i...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1305814110
更新日期:2013-06-11 00:00:00
abstract::A comparison of five constant region sequences of human and mouse k and lambda immunoglobulin chains has been undertaken in order to reveal sequence homologies and evolutionary relationships. Simultaneously, a comparison with the three-dimensional structure of one mouse k-chain (McPC 603) has suggested structural reas...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.72.7.2785
更新日期:1975-07-01 00:00:00
abstract::Transgenic mice have provided invaluable information about gene function and regulation. However, because of marked differences between rodents and primates, some areas of human biology such as early embryonic development, aging, and maternal-fetal interactions would be best studied in a nonhuman primate model. Here, ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.181336098
更新日期:2001-09-11 00:00:00
abstract::A general model is proposed for genetic recombination. Its essential new feature is the hypothesis that recombination is initiated by a single-strand (or asymmetric) transfer, which may, after isomerization, become a two-strand (or symmetric) exchange. The likelihood of this transition from asymmetric to symmetric str...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.72.1.358
更新日期:1975-01-01 00:00:00
abstract::Saccharomyces cerevisiae is one of the most important model organisms and has been a valuable asset to human civilization. However, despite its extensive use in the last 9,000 y, the existence of a seasonal cycle outside human-made environments has not yet been described. We demonstrate the role of social wasps as vec...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1208362109
更新日期:2012-08-14 00:00:00
abstract::Although recent studies have shown that brown adipose tissue (BAT) arises from progenitor cells that also give rise to skeletal muscle, the developmental signals that control the formation of BAT remain largely unknown. Here, we show that brown preadipocytes possess primary cilia and can respond to Hedgehog (Hh) signa...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1420978112
更新日期:2015-04-21 00:00:00
abstract::The diversity of the T cell receptor (TCR) repertoire is limited, because of the processes of positive and negative T cell selection. To obtain T cells with specificities beyond the immune system's capacity, we have developed a strategy for retroviral TCR display. In this approach, a library of T cell variants is gene...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.97.26.14578
更新日期:2000-12-19 00:00:00
abstract::The largest known DNA viruses infect Acanthamoeba and belong to two markedly different families. The Megaviridae exhibit pseudo-icosahedral virions up to 0.7 μm in diameter and adenine-thymine (AT)-rich genomes of up to 1.25 Mb encoding a thousand proteins. Like their Mimivirus prototype discovered 10 y ago, they enti...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1320670111
更新日期:2014-03-18 00:00:00
abstract::Future nuclear arms reduction efforts will require technologies to verify that warheads slated for dismantlement are authentic without revealing any sensitive weapons design information to international inspectors. Despite several decades of research, no technology has met these requirements simultaneously. Recent wor...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1721278115
更新日期:2018-04-24 00:00:00
abstract::Circadian rhythms in metazoan eukaryotes are controlled by an endogenous molecular clock. It functions in many locations, including subsets of brain neurons (clock neurons) within the central nervous system. Although the molecular clock relies on transcription/translation feedback loops, posttranscriptional regulation...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1605837113
更新日期:2016-05-24 00:00:00
abstract::The rotational strengths of the four longer wavelength transitions, B(2u), B(1u), and the two E(1u), of adenosine derivatives constrained in the syn form have been investigated theoretically and experimentally. The theory combines a complete neglect of differential overlap version S (CNDO/S) description of the base wi...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.77.6.3398
更新日期:1980-06-01 00:00:00
abstract::Immobilization antigens of stock 51 of Paramecium tetraurelia were subjected to electrophoresis in NaDodSO(4)/polyacrylamide gels. Type A is estimated to have a molecular size of 300,000 daltons; H is estimated to be 288,000, D to be 280,000, E to be 270,000, B to be 253,000, and C to be 250,000. Poly(A)(+)RNAs have b...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.78.11.6776
更新日期:1981-11-01 00:00:00
abstract::Extracellular growth and differentiation factors induce changes in gene expression in the nucleus by initiating a series of protein associations that alter the subcellular localization of intracellular signaling proteins. Initial events involve receptor homo- or heterodimerization and subsequent recruitment of cytosol...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.93.10.4604
更新日期:1996-05-14 00:00:00
abstract::A recombinant plasmid containing a DNA segment complementary to rat liver albumin mRNA has been constructed, cloned, and used to examine the organization of albumin gene. The 18S fraction of total liver poly(A)-containing RNA was copied into a double-stranded cDNA by avian myeloblastosis virus reverse transcriptase an...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.76.9.4370
更新日期:1979-09-01 00:00:00
abstract::Accumulative aggregation of mutant Huntingtin (Htt) is a primary neuropathological hallmark of Huntington's disease (HD). Currently, mechanistic understanding of the cytotoxicity of mutant Htt aggregates remains limited, and neuroprotective strategies combating mutant Htt-induced neurodegeneration are lacking. Here, w...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1904563116
更新日期:2019-09-17 00:00:00
abstract::Using an expression cloning approach, we have isolated a cDNA encoding GD3 synthase (CMP-NeuAc:NeuAc alpha 2-3Gal beta 1-4Glc beta 1-1'Cer alpha 2,8-sialyltransferase, EC 2.4.99.8), which is a key regulatory enzyme determining the prominence of the ganglioside biosynthesis pathway. The cloned cDNA encodes a 341-amino ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.91.17.7952
更新日期:1994-08-16 00:00:00
abstract::Construction of deletion derivative plasmids and cloning of restriction fragments from plasmids containing the Salmonella typhimurium origin of replication (ori) were used to locate the functional origin to within a DNA fragment of 296 base pairs between the genes uncB and asn. The nucleotide sequence of the S. typhim...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.77.5.2460
更新日期:1980-05-01 00:00:00
abstract::Electrically excitable cells harness voltage-coupled calcium influx to transmit intracellular signals, typically studied in neurons and cardiomyocytes. Despite intense study in higher organisms, investigations of voltage and calcium signaling in bacteria have lagged due to their small size and a lack of sensitive tool...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1703084114
更新日期:2017-08-29 00:00:00
abstract::For a series of different proteins, including a structural protein, enzyme, inhibitor, protein marker, and a charge-transfer system, we have quantified the higher affinity of Na+ over K+ to the protein surface by means of molecular dynamics simulations and conductivity measurements. Both approaches show that sodium bi...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0606959103
更新日期:2006-10-17 00:00:00
abstract::Two striking differences between humans and our closest living relatives, chimpanzees and gorillas, are the size of our brains (larger by a factor of three or four) and our life span (longer by a factor of about two). Our thesis is that these two distinctive features of humans are products of coevolutionary selection....
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.152502899
更新日期:2002-07-23 00:00:00
abstract::The detection, stabilization, and repair of stress-induced damage are essential requirements for cellular life. All cells respond to osmotic stress-induced water loss with increased expression of genes that mediate accumulation of organic osmolytes, solutes that function as chemical chaperones and restore osmotic home...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0602987103
更新日期:2006-08-08 00:00:00
abstract::Cyclodextrins are cyclic oligosaccharides widely used in the pharmaceutical industry to improve drug delivery and to increase the solubility of hydrophobic compounds. Anabaenolysins are lipopeptides produced by cyanobacteria with potent lytic activity in cholesterol-containing membranes. Here, we identified the 23- to...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1510432112
更新日期:2015-11-03 00:00:00
abstract::We previously have shown that proliferating lymphoid cells contain an extractable cytoplasmic protein that is capable of inducing DNA synthesis in isolated quiescent nuclei (activator of DNA replication, ADR). ADR is present in continuously proliferating (transformed) lymphoblastoid cell lines and in mitogen- or inter...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.82.15.5160
更新日期:1985-08-01 00:00:00