scholarly journals Structural basis for the delivery of activated sialic acid into Golgi for sialyation

2019 ◽  
Author(s):  
Emmanuel Nji ◽  
Ashutosh Gulati ◽  
Abdul Aziz Qureshi ◽  
Mathieu Coincon ◽  
David Drew
Keyword(s):  
Crystal Structure ◽  
Sialic Acid ◽  
Structural Basis ◽  
Golgi Membranes ◽  
Secretory Glycoproteins ◽  
Acid Transporter ◽  
Therapeutic Glycoproteins

AbstractThe decoration of secretory glycoproteins and glycolipids with sialic acid is critical to many physiological and pathological processes. Sialyation is dependent on a continuous supply of sialic acid into Golgi organelles in the form of CMP-sialic acid. Translocation of CMP-sialic acid into Golgi is carried out by the CMP-sialic acid transporter (CST). Mutations in human CST are linked to glycosylation disorders, and CST is important for glycopathway engineering, as it is critical for sialyation efficiency of therapeutic glycoproteins. The mechanism of how CMP-sialic acid is recognized and translocated across Golgi membranes in exchange for CMP is poorly understood. Here we have determined the crystal structure of a eukaryotic CMP-sialic acid transporter in complex with CMP. We conclude that the specificity of CST for CMP-sialic acid is established by the nucleotide CMP to such an extent, they are uniquely able to work both as passive and as (secondary) active antiporters.

scholarly journals Structural basis of Naa20 activity towards a canonical NatB substrate

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Dominik Layer ◽  
Jürgen Kopp ◽  
Miriam Fontanillo ◽  
Maja Köhn ◽  
Karine Lapouge ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Drug Development ◽  
Catalytic Mechanism ◽  
Peptide Binding ◽  
Competitive Inhibitor ◽  
Structural Basis ◽  
Substrate Affinity ◽  
Protein Homeostasis ◽  
Auxiliary Subunit

AbstractN-terminal acetylation is one of the most common protein modifications in eukaryotes and is carried out by N-terminal acetyltransferases (NATs). It plays important roles in protein homeostasis, localization, and interactions and is linked to various human diseases. NatB, one of the major co-translationally active NATs, is composed of the catalytic subunit Naa20 and the auxiliary subunit Naa25, and acetylates about 20% of the proteome. Here we show that NatB substrate specificity and catalytic mechanism are conserved among eukaryotes, and that Naa20 alone is able to acetylate NatB substrates in vitro. We show that Naa25 increases the Naa20 substrate affinity, and identify residues important for peptide binding and acetylation activity. We present the first Naa20 crystal structure in complex with the competitive inhibitor CoA-Ac-MDEL. Our findings demonstrate how Naa20 binds its substrates in the absence of Naa25 and support prospective endeavors to derive specific NAT inhibitors for drug development.

scholarly journals Structural basis of antigen recognition: crystal structure of duck egg lysozyme

2017 ◽  
Vol 73 (11) ◽  
pp. 910-920 ◽  
Author(s):  
David Brent Langley ◽  
Ben Crossett ◽  
Peter Schofield ◽  
Jenny Jackson ◽  
Mahdi Zeraati ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Mass Spectrometry ◽  
Binding Affinity ◽  
Anas Platyrhynchos ◽  
Antigen Recognition ◽  
Pekin Duck ◽  
Structural Basis ◽  
Primary Sequence ◽  
Duck Egg ◽  
Differential Affinity

Duck egg lysozyme (DEL) is a widely used model antigen owing to its capacity to bind with differential affinity to anti-chicken egg lysozyme antibodies. However, no structures of DEL have so far been reported, and the situation had been complicated by the presence of multiple isoforms and conflicting reports of primary sequence. Here, the structures of two DEL isoforms from the eggs of the commonly used Pekin duck (Anas platyrhynchos) are reported. Using structural analyses in combination with mass spectrometry, non-ambiguous DEL primary sequences are reported. Furthermore, the structures and sequences determined here enable rationalization of the binding affinity of DEL for well documented landmark anti-lysozyme antibodies.

scholarly journals Host-Selected Amino Acid Changes at the Sialic Acid Binding Pocket of the Parvovirus Capsid Modulate Cell Binding Affinity and Determine Virulence

2006 ◽  
Vol 80 (3) ◽  
pp. 1563-1573 ◽  
Author(s):  
Alberto López-Bueno ◽  
Mari-Paz Rubio ◽  
Nathan Bryant ◽  
Robert McKenna ◽  
Mavis Agbandje-McKenna ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Sialic Acid ◽  
Parallel Evolution ◽  
Attachment Site ◽  
Fibroblast Cell ◽  
Scid Mice ◽  
Wild Type ◽  
Large Plaque ◽  
Capsid Sequence

ABSTRACT The role of receptor recognition in the emergence of virulent viruses was investigated in the infection of severe combined immunodeficient (SCID) mice by the apathogenic prototype strain of the parvovirus minute virus of mice (MVMp). Genetic analysis of isolated MVMp viral clones (n = 48) emerging in mice, including lethal variants, showed only one of three single changes (V325M, I362S, or K368R) in the common sequence of the two capsid proteins. As was found for the parental isolates, the constructed recombinant viruses harboring the I362S or the K368R single substitutions in the capsid sequence, or mutations at both sites, showed a large-plaque phenotype and lower avidity than the wild type for cells in the cytotoxic interaction with two permissive fibroblast cell lines in vitro and caused a lethal disease in SCID mice when inoculated by the natural oronasal route. Significantly, the productive adsorption of MVMp variants carrying any of the three mutations selected through parallel evolution in mice showed higher sensitivity to the treatment of cells by neuraminidase than that of the wild type, indicating a lower affinity of the viral particle for the sialic acid component of the receptor. Consistent with this, the X-ray crystal structure of the MVMp capsids soaked with sialic acid (N-acetyl neuraminic acid) showed the sugar allocated in the depression at the twofold axis of symmetry (termed the dimple), immediately adjacent to residues I362 and K368, which are located on the wall of the dimple, and approximately 22 Å away from V325 in a threefold-related monomer. This is the first reported crystal structure identifying an infectious receptor attachment site on a parvovirus capsid. We conclude that the affinity of the interactions of sialic-acid-containing receptors with residues at or surrounding the dimple can evolutionarily regulate parvovirus pathogenicity and adaptation to new hosts.

scholarly journals Crystal structure of human angiogenin reveals the structural basis for its functional divergence from ribonuclease.

1994 ◽  
Vol 91 (8) ◽  
pp. 2915-2919 ◽  
Author(s):  
K. R. Acharya ◽  
R. Shapiro ◽  
S. C. Allen ◽  
J. F. Riordan ◽  
B. L. Vallee
Keyword(s):  
Crystal Structure ◽  
Functional Divergence ◽  
Structural Basis

scholarly journals The Golgi CMP-sialic acid transporter: A new CHO mutant provides functional insights

Glycobiology ◽  
2008 ◽  
Vol 18 (11) ◽  
pp. 851-860 ◽  
Author(s):  
S. F. Lim ◽  
M. M. Lee ◽  
P. Zhang ◽  
Z. Song
Keyword(s):  
Sialic Acid ◽  
Acid Transporter

scholarly journals The Lysosomal Sialic Acid Transporter Sialin Is Required for Normal CNS Myelination

2009 ◽  
Vol 29 (49) ◽  
pp. 15355-15365 ◽  
Author(s):  
L. M. Prolo ◽  
H. Vogel ◽  
R. J. Reimer
Keyword(s):  
Sialic Acid ◽  
Acid Transporter ◽  
Cns Myelination
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