ARTICLE Backbone 1 H, 15 N, 13 C and Ile, Leu, Val methyl chemical shift assignments for the 33.5 kDa N-terminal domain of Candida albicans ALS1 Robert Yan • Peter J. Simpson • Stephen J. Matthews • Ernesto Cota Received: 14 May 2010 / Accepted: 7 June 2010 / Published online: 17 June 2010 Ó Springer Science+Business Media B.V. 2010 Abstract The agglutinin-like-sequence (ALS) family of adhesion proteins are a key virulence factor for C. albicans. These proteins have been implicated in several functions, notably adhesion and invasion of different cell types, as well as binding to peptides and proteins in the cell surface and extracellular matrix. In order to understand their binding mechanism and en route to a full structural deter- mination by NMR, here we report the resonance assign- ments of backbone atoms plus Ile, Leu and Val methyls for residues 18–329 of ALS1, which comprises the 33.5 kDa binding domain. Keywords NMR  Candida albicans  Adhesin  Structure  ALS  Agglutinin-like sequence  Resonance assignment Biological context Candida albicans is a commensal organism of the skin and mucous membranes of the gut, oropharynx and vagina, with the potential to cause superficial infections in healthy hosts such as vaginal candidiasis and oral thrush. Among patients that become immunocompromised through disease or medical practices, C. albicans and other Candida spp. have emerged as the sixth most frequently isolated patho- gen in hospitals (Jarvis 1995; Pfaller and Diekema 2007) and the fourth most frequent cause of nosocomial blood stream infections (BSI). C. albicans alone accounts for 37–70% of Candida BSI, which carry a high rate (*50%) of attributable mortality (Gudlaugsson et al. 2003). One of the key factors for C. albicans colonisation and pathogenicity is its adhesive phenotype. Amongst its armoury of adhesins are the agglutinin-like sequence (ALS) family (Hoyer et al. 2008). This family comprises eight cell surface glycoproteins, ALS1 to ALS7 and ALS9 (Hoyer 2001) associated with cell adhesion/invasion and broad binding specificity to peptides and extracellular proteins (Gaur and Klotz 2004; Sheppard et al. 2004). Each member consists of an N-terminal binding domain (with sequence identities ranging from *41 to 84%), a non-repeat Thr-rich region of 103 residues, a variable number of 36-residue tandem repeats, and a variable C-terminal domain that anchors to the cell wall via a glycophosphatidylinositol (GPI) anchor. The tandem repeats and C-terminal domain are highly glycosylated. The N-terminal domain has been directly involved in the binding of different cell types (Loza et al. 2004) and is predicted to have an immunoglobulin-like fold (Sheppard et al. 2004). Here we present the chemical shift assignments of backbone and Ile, Leu and Val methyls for residues 18–329 of ALS1. Methods and experiments A DNA fragment of C. albicans ALS1 residues 18–329 (GenBank XM_712984) was kindly provided by Prof. Lois Hoyer (University of Illinois at Urbana-Champaign). The CTG codon of residue 303 (expressed as Ser in C. albi- cans) was mutated to TCT. The gene was subcloned into pET-32 Xa/LIC (Novagen) to express ALS1 18–329 as a fusion protein with N-terminal thioredoxin and His 6 tags. For protein expression, this vector was transformed into Escherichia coli Origami TM B(DE3)pLysS (Novagen). R. Yan  P. J. Simpson  S. J. Matthews  E. Cota (&) Division of Molecular Biosciences, Imperial College London, South Kensington, London SW7 2AZ, UK e-mail: e.cota@imperial.ac.uk 123 Biomol NMR Assign (2010) 4:187–190 DOI 10.1007/s12104-010-9243-8