@article {348,
	title = {The calcium activation of gelsolin: Insights from the 3 angstrom structure of the G4-G6/actin complex},
	journal = {Journal of Molecular Biology},
	volume = {324},
	number = {4},
	year = {2002},
	note = {ISI Document Delivery No.: 625PRTimes Cited: 48Cited Reference Count: 32},
	month = {Dec},
	pages = {691-702},
	type = {Article},
	abstract = {Gelsolin participates in the reorganization of the actin cytoskeleton that is required during such phenomena as cell movement, cytokinesis, and apoptosis. It consists of six structurally similar domains, G1-G6, which are arranged at resting intracellular levels of calcium ion so as to obscure the three actin-binding surfaces. Elevation of Ca2+ concentrations releases latches within the constrained structure and produces large shifts in the relative positioning of the domains, permitting gelsolin to bind to and sever actin filaments. How Ca2+ is able to activate gelsolin has been a major question concerning the function of this protein. We present the improved structure of the C-terminal half of gelsolin bound to monomeric actin at 3.0 Angstrom resolution. Two classes of Ca2+-binding site are evident on gelsolin: type 1 sites share coordination of Ca2+ with actin, while type 2 sites are wholly contained within gelsolin. This structure of the complex reveals the locations of two novel metal ion-binding sites in domains G5 and G6, respectively. We identify both as type 2 sites. The absolute conservation of the type 2 calcium-ligating residues across the six,domains of gelsolin suggests that this site exists in each of the domains. In total, gelsolin has the potential to bind eight calcium ions, two type 1 and six type 2. The function of the type 2 sites is to facilitate structural rearrangements within gelsolin as part of the activation and actin-binding and severing processes. We propose the novel type 2 site in G6 to be the critical site that initiates overall activation of gelsolin by releasing the tail latch that locks calcium-free gelsolin in a conformation unable to bind actin. (C) 2002 Elsevier Science Ltd. All rights reserved.},
	keywords = {actin, ACTIVATION, ACTOPHORIN, BINDING DOMAIN, CA2+, calcium, CAPPING PROTEIN, F-ACTIN, FAMILIAL AMYLOIDOSIS, FINNISH TYPE, gelsolin, IDENTIFICATION, MECHANISM, PLASMA GELSOLIN, REGULATION, severing},
	isbn = {0022-2836},
	url = {<Go to ISI>://000179825300011},
	author = {Choe, H. and Burtnick, L. D. and Mejillano, M. and Yin, H. L. and Robinson, R. C. and Choe, S.}
}
@article {389,
	title = {The solution structure and interactions of CheW from Thermotoga maritima},
	journal = {Nature Structural Biology},
	volume = {9},
	number = {2},
	year = {2002},
	note = {ISI Document Delivery No.: 516PHTimes Cited: 35Cited Reference Count: 34},
	month = {Feb},
	pages = {121-125},
	type = {Article},
	abstract = {Using protein from the hyperthermophile Thermotoga maritima, we have determined the solution structure of CheW, an essential component in the formation of the bacterial chemotaxis signaling complex. The overall fold is similar to the regulatory domain of the chemotaxis kinase CheA. In addition, interactions of CheW with CheA were monitored by nuclear magnetic resonance (NMR) techniques. The chemical shift perturbation data show the probable contacts that CheW makes with CheA. In combination with previous genetic data, the structure also suggests a possible binding site for the chemotaxis receptor. These results provide a structural basis for a model in which CheW acts as a molecular bridge between CheA and the cytoplasmic tails of the receptor.},
	keywords = {BACTERIAL CHEMOTAXIS, BINDING DOMAIN, C-13-LABELED PROTEINS, ESCHERICHIA-COLI, HISTIDINE KINASE, KINASE CHEA, NMR EXPERIMENTS, RESONANCE ASSIGNMENTS, SECONDARY STRUCTURE, SIGNAL-TRANSDUCTION},
	isbn = {1072-8368},
	url = {<Go to ISI>://000173562000015},
	author = {Griswold, I. J. and Zhou, H. J. and Matison, M. and Swanson, R. V. and McIntosh, L. P. and Simon, M. I. and Dahlquist, F. W.}
}
@article {4312,
	title = {Equus caballus gelsolin - cDNA sequence and protein structural implications},
	journal = {European Journal of Biochemistry},
	volume = {251},
	number = {3},
	year = {1998},
	note = {ISI Document Delivery No.: YV719Times Cited: 4Cited Reference Count: 48},
	month = {Feb},
	pages = {613-621},
	type = {Article},
	abstract = {We have generated and characterized the cDNA from equine smooth muscle that Encodes gelsolin, an actin-modulating protein. Overlapping cDNA clones synthesized by the reverse transcriptaseoplymerase chain reaction and clones isolated from a horse genomic library provided the complete primary structure for the intracellular isoform of gelsolin, while cDNA complemented with protein sequence data produced the full-length primary transcript of the gelsolin isoform found circulating in equine plasma. The deduced amino acid sequences of the intracellular and secreted versions of equine gelsolin infer polypeptides of 731 and 755 residues with apparent molecular masses of 80.7 kDa and 83.2 kDa, respectively. Multiple sequence alignment analysis of equine, human, porcine, and murine orthologs of gelsolin demonstrates prominent similarities among all of these proteins, with the horse and human molecules exhibiting the largest degree of likeness with respect to polypeptide length and overall sequence composition. Both horse and human plasma gelsolins are comprised of 755 amino acids with 94\% of the residues identical, while the degree of sequence identity in the shorter (731 residues) cytoplasmic gelsolins is 95 \%. Analysis of the sequences and structures of the six related domains that comprise gelsolin emphasizes the strong correlation that exists between primary structural conservation among mammalian gelsolins and maintenance of the three-dimensional domain fold characteristic of members of this protein family.},
	keywords = {actin-binding protein, ACTIN-SEVERING PROTEINS, amino acid sequence, AMPLIFICATION, BINDING DOMAIN, cDNA sequence, CLONING, CYTOPLASMIC FORMS, DNA, END, extraction, gelsolin, HORSE PLASMA GELSOLIN, MUSCLE, protein structure},
	isbn = {0014-2956},
	url = {<Go to ISI>://000071855900009},
	author = {Koepf, E. K. and Hewitt, J. and Vo, H. and MacGillivray, R. T. A. and Burtnick, L. D.}
}
@article {3920,
	title = {The crystal structure of plasma gelsolin: Implications for actin severing, capping, and nucleation},
	journal = {Cell},
	volume = {90},
	number = {4},
	year = {1997},
	note = {ISI Document Delivery No.: XT066Times Cited: 164Cited Reference Count: 50},
	month = {Aug},
	pages = {661-670},
	type = {Article},
	abstract = {The structure of gelsolin has been determined by crystallography and comprises six structurally related domains that, in a Ca2+-free environment, pack together to form a compact globular structure in which the putative actin-binding sequences are not sufficiently exposed to enable binding to occur. We propose that binding Ca2+ can release the connections that join the N- and C-terminal halves of gelsolin, enabling each half to bind actin relatively independently. Domain shifts are proposed in response to Ca2+ as bases for models of how gelsolin acts to sever, cap, or nucleate F-actin filaments. The structure also invites discussion of polyphosphoinositide binding to segment 2 and suggests how mutation at Asp-187 could initiate a series of events that lead to deposition of amyloid plaques, as observed in victims of familial amyloidosis (Finnish type).},
	keywords = {AMYLOIDOSIS, BINDING DOMAIN, calcium, DEFINITION, F-ACTIN, FILAMENT, IDENTIFICATION, PROTEIN, SEQUENCE, VILLIN},
	isbn = {0092-8674},
	url = {<Go to ISI>://A1997XT06600010},
	author = {Burtnick, L. D. and Koepf, E. K. and Grimes, J. and Jones, E. Y. and Stuart, D. I. and McLaughlin, P. J. and Robinson, R. C.}
}
@article {2845,
	title = {HORSE PLASMA GELSOLIN LABELED WITH FLUORESCEIN ISOTHIOCYANATE RESPONDS TO CALCIUM AND ACTIN},
	journal = {European Journal of Biochemistry},
	volume = {212},
	number = {3},
	year = {1993},
	note = {ISI Document Delivery No.: KT704Times Cited: 7Cited Reference Count: 26},
	month = {Mar},
	pages = {713-718},
	type = {Article},
	abstract = {Reaction between horse plasma gelsolin and fluorescein-5-isothiocyanate (FITC) resulted in incorporation of 4.8 +/- 0.6 fluorescein groups/gelsolin molecule. The sites of modification were not clustered in any one portion of the gelsolin polypeptide chain; all major peptides produced by proteolytic digestion with alpha-chymotrypsin exhibited a fluorescence characteristic of fluorescein. FITC-gelsolin has a peptide-backbone circular dichroism spectrum at 20-degrees-C that is indistinguishable from that of native gelsolin, but FITC-gelsolin is considerably more resistant than native gelsolin to thermally induced precipitation. FITC-gelsolin is fully able to carry out severing of F-actin filaments, the prime function of gelsolin in plasma. An opening up of the structure of gelsolin on binding Ca2+ is evident from an increased susceptibility of FITC-gelsolin to quenching by I-. Ca2+ dependence of the interaction between gelsolin and actin is evident in titrations both of intensity and polarization of the fluorescence of FITC-gelsolin solutions. A Ca2+-sensitive interaction between gelsolin and tropomyosin also is observed.},
	keywords = {BINDING DOMAIN, FILAMENTS, PROTEIN, TROPOMYOSIN},
	isbn = {0014-2956},
	url = {<Go to ISI>://A1993KT70400010},
	author = {Koepf, E. K. and Burtnick, L. D.}
}
