Structural basis of matrix metalloproteinase function

2003 ◽  
Vol 70 ◽  
pp. 1-14 ◽  
Author(s):  
Wolfram Bode

The matrix metalloproteinases (MMPs) constitute a family of multidomain zinc endopeptidases which contain a catalytic domain with a common metzincin-like topology. The MMPs are involved not only in extracellular matrix degradation, but also in a number of other biological processes. Normally, their proteolytic activity is regulated precisely by their main endogenous protein inhibitors, in particular the tissue inhibitors of metalloproteinases (TIMPs). Disruption of this balance results in serious diseases, such as arthritis, tumour growth and metastasis, rendering the MMPs attractive targets for inhibition therapy. Knowledge of their tertiary structures is crucial for a full understanding of their functional properties. Since the first publication of atomic MMP structures in 1994, much more structural information has become available on details of the catalytic domain, on its interaction with synthetic and protein inhibitors, on domain organization and on the formation of complexes with other proteins. This review will outline our current knowledge of MMP structure.

2003 ◽  
Vol 70 ◽  
pp. 201-212 ◽  
Author(s):  
Hideaki Nagase ◽  
Keith Brew

The tissue inhibitors of metalloproteinases (TIMPs) are endogenous inhibitors of the matrix metalloproteinases (MMPs), enzymes that play central roles in the degradation of extracellular matrix components. The balance between MMPs and TIMPs is important in the maintenance of tissues, and its disruption affects tissue homoeostasis. Four related TIMPs (TIMP-1 to TIMP-4) can each form a complex with MMPs in a 1:1 stoichiometry with high affinity, but their inhibitory activities towards different MMPs are not particularly selective. The three-dimensional structures of TIMP-MMP complexes reveal that TIMPs have an extended ridge structure that slots into the active site of MMPs. Mutation of three separate residues in the ridge, at positions 2, 4 and 68 in the amino acid sequence of the N-terminal inhibitory domain of TIMP-1 (N-TIMP-1), separately and in combination has produced N-TIMP-1 variants with higher binding affinity and specificity for individual MMPs. TIMP-3 is unique in that it inhibits not only MMPs, but also several ADAM (a disintegrin and metalloproteinase) and ADAMTS (ADAM with thrombospondin motifs) metalloproteinases. Inhibition of the latter groups of metalloproteinases, as exemplified with ADAMTS-4 (aggrecanase 1), requires additional structural elements in TIMP-3 that have not yet been identified. Knowledge of the structural basis of the inhibitory action of TIMPs will facilitate the design of selective TIMP variants for investigating the biological roles of specific MMPs and for developing therapeutic interventions for MMP-associated diseases.


2013 ◽  
Vol 394 (8) ◽  
pp. 977-993 ◽  
Author(s):  
Torsten Schöneberg ◽  
Marco Kloos ◽  
Antje Brüser ◽  
Jürgen Kirchberger ◽  
Norbert Sträter

Abstract Although the crystal structures of prokaryotic 6-phosphofructokinase, a key enzyme of glycolysis, have been available for almost 25 years now, structural information about the more complex and highly regulated eukaryotic enzymes is still lacking until now. This review provides an overview of the current knowledge of eukaryotic 6-phosphofructokinase based on recent crystal structures, kinetic analyses and site-directed mutagenesis data with special focus on the molecular architecture and the structural basis of allosteric regulation.


2021 ◽  
Author(s):  
Sue Im Sim ◽  
Yuanyuan Chen ◽  
Eunyong Park

Mitochondria import nearly all their ~1,000-2,000 constituent proteins from the cytosol across their double membrane envelope. Genetic and biochemical studies have shown that the conserved protein translocase, termed the TIM complex (also known as TIM23 complex), mediates import of presequence-containing proteins into the mitochondrial matrix and inner membrane. Among ~10 different subunits of the complex, the essential multi-pass membrane protein Tim23, together with the evolutionarily related protein Tim17, has long been postulated to form a protein-conducting channel. However, the mechanism of TIM-mediated protein import remains uncertain due to a lack of structural information on the complex. Here, we have determined the cryo-EM structure of the core TIM complex (Tim17-Tim23-Tim44) from Saccharomyces cerevisiae. We show that, contrary to the prevailing model, Tim23 and Tim17 do not form a water-filled channel, but instead have separate, lipid-exposed concave cavities that face in opposite directions. Remarkably, our data suggest that the cavity of Tim17 itself forms the protein translocation path whereas Tim23 plays a structural role. We also show how the Tim17-Tim23 heterodimer associates with the scaffold protein Tim44 and J-domain proteins to mediate Hsp70-driven polypeptide transport into the matrix. Our work provides the structural foundation to understand the mechanism of TIM-mediated protein import and sorting, a central pathway in mitochondrial biogenesis.


2019 ◽  
Vol 476 (21) ◽  
pp. 3227-3240 ◽  
Author(s):  
Shanshan Wang ◽  
Yanxiang Zhao ◽  
Long Yi ◽  
Minghe Shen ◽  
Chao Wang ◽  
...  

Trehalose-6-phosphate (T6P) synthase (Tps1) catalyzes the formation of T6P from UDP-glucose (UDPG) (or GDPG, etc.) and glucose-6-phosphate (G6P), and structural basis of this process has not been well studied. MoTps1 (Magnaporthe oryzae Tps1) plays a critical role in carbon and nitrogen metabolism, but its structural information is unknown. Here we present the crystal structures of MoTps1 apo, binary (with UDPG) and ternary (with UDPG/G6P or UDP/T6P) complexes. MoTps1 consists of two modified Rossmann-fold domains and a catalytic center in-between. Unlike Escherichia coli OtsA (EcOtsA, the Tps1 of E. coli), MoTps1 exists as a mixture of monomer, dimer, and oligomer in solution. Inter-chain salt bridges, which are not fully conserved in EcOtsA, play primary roles in MoTps1 oligomerization. Binding of UDPG by MoTps1 C-terminal domain modifies the substrate pocket of MoTps1. In the MoTps1 ternary complex structure, UDP and T6P, the products of UDPG and G6P, are detected, and substantial conformational rearrangements of N-terminal domain, including structural reshuffling (β3–β4 loop to α0 helix) and movement of a ‘shift region' towards the catalytic centre, are observed. These conformational changes render MoTps1 to a ‘closed' state compared with its ‘open' state in apo or UDPG complex structures. By solving the EcOtsA apo structure, we confirmed that similar ligand binding induced conformational changes also exist in EcOtsA, although no structural reshuffling involved. Based on our research and previous studies, we present a model for the catalytic process of Tps1. Our research provides novel information on MoTps1, Tps1 family, and structure-based antifungal drug design.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Steinar Halldorsson ◽  
Kasim Sader ◽  
Jack Turner ◽  
Lesley J. Calder ◽  
Peter B. Rosenthal

AbstractThe lipid-enveloped influenza C virus contains a single surface glycoprotein, the haemagglutinin-esterase-fusion (HEF) protein, that mediates receptor binding, receptor destruction, and membrane fusion at the low pH of the endosome. Here we apply electron cryotomography and subtomogram averaging to describe the structural basis for hexagonal lattice formation by HEF on the viral surface. The conformation of the glycoprotein in situ is distinct from the structure of the isolated trimeric ectodomain, showing that a splaying of the membrane distal domains is required to mediate contacts that form the lattice. The splaying of these domains is also coupled to changes in the structure of the stem region which is involved in membrane fusion, thereby linking HEF’s membrane fusion conformation with its assembly on the virus surface. The glycoprotein lattice can form independent of other virion components but we show a major role for the matrix layer in particle formation.


Author(s):  
Qiujia Chen ◽  
Millie Georgiadis

Transposable elements have played a critical role in the creation of new genes in all higher eukaryotes, including humans. Although the chimeric fusion protein SETMAR is no longer active as a transposase, it contains both the DNA-binding domain (DBD) and catalytic domain of theHsmar1transposase. The amino-acid sequence of the DBD has been virtually unchanged in 50 million years and, as a consequence, SETMAR retains its sequence-specific binding to the ancestralHsmar1terminal inverted repeat (TIR) sequence. Thus, the DNA-binding activity of SETMAR is likely to have an important biological function. To determine the structural basis for the recognition of TIR DNA by SETMAR, the design of TIR-containing oligonucleotides and SETMAR DBD variants, crystallization of DBD–DNA complexes, phasing strategies and initial phasing experiments are reported here. An unexpected finding was that oligonucleotides containing two BrdUs in place of thymidines produced better quality crystals in complex with SETMAR than their natural counterparts.


mBio ◽  
2017 ◽  
Vol 8 (3) ◽  
Author(s):  
Matthew J. Belousoff ◽  
Zohar Eyal ◽  
Mazdak Radjainia ◽  
Tofayel Ahmed ◽  
Rebecca S. Bamert ◽  
...  

ABSTRACT An unorthodox, surprising mechanism of resistance to the antibiotic linezolid was revealed by cryo-electron microscopy (cryo-EM) in the 70S ribosomes from a clinical isolate of Staphylococcus aureus. This high-resolution structural information demonstrated that a single amino acid deletion in ribosomal protein uL3 confers linezolid resistance despite being located 24 Å away from the linezolid binding pocket in the peptidyl-transferase center. The mutation induces a cascade of allosteric structural rearrangements of the rRNA that ultimately results in the alteration of the antibiotic binding site. IMPORTANCE The growing burden on human health caused by various antibiotic resistance mutations now includes prevalent Staphylococcus aureus resistance to last-line antimicrobial drugs such as linezolid and daptomycin. Structure-informed drug modification represents a frontier with respect to designing advanced clinical therapies, but success in this strategy requires rapid, facile means to shed light on the structural basis for drug resistance (D. Brown, Nat Rev Drug Discov 14:821–832, 2015, https://doi.org/10.1038/nrd4675 ). Here, detailed structural information demonstrates that a common mechanism is at play in linezolid resistance and provides a step toward the redesign of oxazolidinone antibiotics, a strategy that could thwart known mechanisms of linezolid resistance. IMPORTANCE The growing burden on human health caused by various antibiotic resistance mutations now includes prevalent Staphylococcus aureus resistance to last-line antimicrobial drugs such as linezolid and daptomycin. Structure-informed drug modification represents a frontier with respect to designing advanced clinical therapies, but success in this strategy requires rapid, facile means to shed light on the structural basis for drug resistance (D. Brown, Nat Rev Drug Discov 14:821–832, 2015, https://doi.org/10.1038/nrd4675 ). Here, detailed structural information demonstrates that a common mechanism is at play in linezolid resistance and provides a step toward the redesign of oxazolidinone antibiotics, a strategy that could thwart known mechanisms of linezolid resistance.


2021 ◽  
Vol 22 (3) ◽  
pp. 997
Author(s):  
Livija Tušar ◽  
Aleksandra Usenik ◽  
Boris Turk ◽  
Dušan Turk

Protein inhibitors of proteases are an important tool of nature to regulate and control proteolysis in living organisms under physiological and pathological conditions. In this review, we analyzed the mechanisms of inhibition of cysteine proteases on the basis of structural information and compiled kinetic data. The gathered structural data indicate that the protein fold is not a major obstacle for the evolution of a protease inhibitor. It appears that nature can convert almost any starting fold into an inhibitor of a protease. In addition, there appears to be no general rule governing the inhibitory mechanism. The structural data make it clear that the “lock and key” mechanism is a historical concept with limited validity. However, the analysis suggests that the shape of the active site cleft of proteases imposes some restraints. When the S1 binding site is shaped as a pocket buried in the structure of protease, inhibitors can apply substrate-like binding mechanisms. In contrast, when the S1 binding site is in part exposed to solvent, the substrate-like inhibition cannot be employed. It appears that all proteases, with the exception of papain-like proteases, belong to the first group of proteases. Finally, we show a number of examples and provide hints on how to engineer protein inhibitors.


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