Refined crystal structures of Escherichia coli and chicken liver dihydrofolate reductase containing bound trimethoprim.

Matthews, David A.; Bolin, J.T.; Burridge, Jane M.; Filman, David J.; Volz, Karl; Kaufman, Bernard T.; Beddell, C.R.; Champness, J.N.; Stammers, D.K.; Kraut, Joseph

doi:10.1016/s0021-9258(18)89743-5

Cited by 282 publications

(91 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Based on its average protein content of 0.1 pg (Bahr and Zeitler, 1962) a single average mitochondrion was able to accumulate 4,200 molecules of pb2DHFR spanning contact sites. Since the three-dimensional structure of dihydrofolate reductase is known (Volz et al, 1982;Matthews et al, 1985) one may compare the area occupied by these intermediates with the total area of close contact between the two membranes. It can be estimated that the DHFR parts of the membrane spanning intermediates occupied roughly 10-20% of the area of contact site regions corresponding to 0.7-1.4 % of the total outer membrane surface.…”

Section: Contact Site Regions In Neurospora Mitochondriamentioning

confidence: 99%

Translocation arrest by reversible folding of a precursor protein imported into mitochondria. A means to quantitate translocation contact sites.

Rassow

Guiard

Wienhues

et al. 1989

The Journal of Cell Biology

206

149

View full text Add to dashboard Cite

Abstract. Passage of precursor proteins through translocation contact sites of mitochondria was investigated by studying the import of a fusion protein consisting of the NH2-terminal 167 amino acids of yeast cytochrome b2 precursor and the complete mouse dihydrofolate reductase. Isolated mitochondria of Neurospora crassa readily imported the fusion protein. In the presence of methotrexate import was halted and a stable intermediate spanning both mitochondrial membranes at translocation contact sites accumulated. The complete dihydrofolate reductase moiety in this intermediate was external to the outer membrane, and the 136 amino acid residues of the cytochrome b2 moiety remaining after cleavage by the matrix processing peptidase spanned both outer and inner membranes. Removal of methotrexate led to import of the intermediate retained at the contact site into the matrix.Thus unfolding at the surface of the outer mitochondrial membrane is a prerequisite for passage through translocation contact sites. The membrane-spanning intermediate was used to estimate the number of translocation sites. Saturation was reached at 70 pmol intermediate per milligram of mitochondrial protein. This amount of translocation intermediates was calculated to occupy ,x,l% of the total surface of the outer membrane. The morphometrically determined area of close contact between outer and inner membranes corresponded to ~7 % of the total outer membrane surface. Accumulation of the intermediate inhibited the import of other precursor proteins suggesting that different precursor proteins are using common translocation contact sites. We conclude that the machinery for protein translocation into mitochondria is present at contact sites in limited number.

show abstract

Section: Contact Site Regions In Neurospora Mitochondriamentioning

confidence: 99%

Translocation arrest by reversible folding of a precursor protein imported into mitochondria. A means to quantitate translocation contact sites.

Rassow

Guiard

Wienhues

et al. 1989

The Journal of Cell Biology

206

149

View full text Add to dashboard Cite

show abstract

“…Pneumocystis carinii [14], chicken [15], mouse [16] and human [17]. Despite the low level of sequence identity, the three-dimensional structures of DHFR from these different organisms are similar.…”

Section: Introductionmentioning

confidence: 99%

Structural features of halophilicity derived from the crystal structure of dihydrofolate reductase from the Dead Sea halophilic archaeon, Haloferax volcanii

et al. 1998

View full text Add to dashboard Cite

The moderately halophilic behavior of hv-DHFR is consistent with the lack of striking structural features expected to occur in extremely halophilic proteins. The most notable feature of halophilicity is the presence of clusters of non-interacting negatively charged residues. Such clusters are associated with unfavorable electrostatic energy at low salt concentrations, and may account for the instability of hv-DHFR at salt concentrations lower than 0.5 M. With respect to catalysis, the open conformation seen here is indicative of a conformational transition not reported previously. The impact of this conformation on function and/or halophilicity is unknown.

show abstract

“…E. coli, chicken, mouse L1210 and human enzymes. A difference in conformation has been found for trimethoprim between bacterial and vertebrate enzymes [13]. This has been attributed to a slightly larger active site in the vertebrate enzyme resulting in weaker binding of trimethoprim.…”

Section: Introductionmentioning

confidence: 99%

The structure of Pneumocystis carinii dihydrofolate reductase to 1.9 å resolution

et al. 1994

View full text Add to dashboard Cite

These structures show how two drugs interact with a fungal DHFR. A comparison of the three-dimensional structure of this relatively large DHFR with bacterial or mammalian enzyme-inhibitor complexes determined previously highlights some additional secondary structure elements in this particular enzyme species. These comparisons provide further insight into the principles governing DHFR-inhibitor interaction, in which the volume of the active site appears to determine the strength of inhibitor binding.

show abstract

Refined crystal structures of Escherichia coli and chicken liver dihydrofolate reductase containing bound trimethoprim.

Cited by 282 publications

References 25 publications

Translocation arrest by reversible folding of a precursor protein imported into mitochondria. A means to quantitate translocation contact sites.

Translocation arrest by reversible folding of a precursor protein imported into mitochondria. A means to quantitate translocation contact sites.

Structural features of halophilicity derived from the crystal structure of dihydrofolate reductase from the Dead Sea halophilic archaeon, Haloferax volcanii

The structure of Pneumocystis carinii dihydrofolate reductase to 1.9 å resolution

Contact Info

Product

Resources

About