A recent development in quantum chemistry has established the quantum mutual information between orbitals as a major descriptor of electronic structure. This has already facilitated remarkable improvements in numerical methods and may lead to a more comprehensive foundation for chemical bonding theory. Building on this promising development, our work provides a refined discussion of quantum information theoretical concepts by introducing the physical correlation and its separation into classical and quantum parts as distinctive quantifiers of electronic structure. In particular, we succeed in quantifying the entanglement. Intriguingly, our results for different molecules reveal that the total correlation between orbitals is mainly classical, raising questions about the general significance of entanglement in chemical bonding. Our work also shows that implementing the fundamental particle number superselection rule, so far not accounted for in quantum chemistry, removes a major part of correlation and entanglement seen previously. In that respect, realizing quantum information processing tasks with molecular systems might be more challenging than anticipated.

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Tuberculosis (TB) is a global health concern, and this situation has further worsened due to the emergence of drug-resistant strains and the failure of BCG vaccine to impart protection. There is an imperative need to develop highly sensitive, specific diagnostic tools, novel therapeutics, and vaccines for the eradication of TB. In the present study, a chemical screen of a pharmacologically active compound library was performed to identify antimycobacterial compounds. The phenotypic screen identified a few novel small-molecule inhibitors, including NU-6027, a known CDK-2 inhibitor. We demonstrate that NU-6027 inhibits Mycobacterium bovis BCG growth in vitro and also displayed cross-reactivity with Mycobacterium tuberculosis protein kinase D (PknD) and protein kinase G (PknG). Comparative structural and sequence analysis along with docking simulation suggest that the unique binding site stereochemistry of PknG and PknD accommodates NU-6027 more favorably than other M. tuberculosis Ser/Thr protein kinases. Further, we also show that NU-6027 treatment induces the expression of proapoptotic genes in macrophages. Finally, we demonstrate that NU-6027 inhibits M. tuberculosis growth in both macrophage and mouse tissues. Taken together, these results indicate that NU-6027 can be optimized further for the development of antimycobacterial agents.

A fundamental task in any physical theory is to quantify certain physical quantity in a meaningful way. In this paper we show that both fidelity distance and affinity distance satisfy the strong contractibility, and the corresponding resource quantifiers can be used to characterize a large class of resource theories. Under two assumptions, namely, convexity of "free states" and closure of free states under "selective free operations", our general framework of resource theory includes quantum resource theories of entanglement, coherence, partial coherence and superposition. In partial coherence theory, we show that fidelity partial coherence of a bipartite state is equal to the minimal error probability of a mixed quantum state discrimination (QSD) task and vice versa, which complements the main result in [Xiong and Wu, J. Phys. A: Math. Theor. 51, 414005 (2018)]. We also compute the analytic expression of fidelity partial coherence for (2, n) bipartite X-states. At last, we study the correlated coherence in the framework of partial coherence theory. We show that partial coherence of a bipartite state, with respect to the eigenbasis of a subsystem, is actually a measure of quantum correlation. a family of resource quantifiers such as robustness monotones and norm-based quantifiers, etc.

Surface proteins in Gram-positive bacteria are incorporated into the cell wall through a peptide ligation reaction catalyzed by transpeptidase sortase. Six main classes (A-F) of sortase have been identified of which class A sortase is meant for housekeeping functions. The prototypic housekeeping sortase A (SaSrtA) from cleaves LPTG-containing proteins at the scissile T-G peptide bond and ligates protein-LPT to the terminal Gly residue of the nascent cross-bridge of peptidoglycan lipid II precursor. Sortase-mediated ligation ("sortagging") of LPTG-containing substrates and Gly-terminated nucleophiles occurs as well as in the presence of Ca and has been applied extensively for protein conjugations. Although the majority of applications emanate from SaSrtA, low catalytic efficiency, LPTG specificity restriction, and Ca requirement (particularly for applications) remain a drawback. Given that Gram-positive bacteria genomes encode a variety of sortases, natural sortase mining can be a viable complementary approach akin to engineering of wild-type SaSrtA. Here, we describe the structure and specificity of a new class E sortase (SavSrtE) annotated to perform housekeeping roles in Biochemical experiments define the attributes of an optimum peptide substrate, demonstrate Ca-independent activity, and provide insights about contrasting functional characteristics of SavSrtE and SaSrtA. Crystal structure, substrate docking, and mutagenesis experiments have identified a critical residue that dictates the preference for a non-canonical LATG recognition motif over LPTG. These results have implications for rational tailoring of substrate tolerance in sortases. Besides, Ca-independent orthogonal specificity of SavSrtE is likely to expand the sortagging toolkit.

We consider a quantum particle (walker) on a line who coherently chooses to jump to the left or right depending on the result of toss of a quantum coin. The lengths of the jumps are considered to be independent and identically distributed quenched Poisson random variables. We find that the spread of the walker is significantly inhibited, whereby it resides in the near-origin region, with respect to the case when there is no disorder. The scaling exponent of the quenched-averaged dispersion of the walker is sub-ballistic but super-diffusive. We also show that the features are universal to a class of sub-and super-Poissonian distributed quenched randomized jumps.

Sortases are cell-membrane-anchored cysteine transpeptidases that are essential for the assembly and anchoring of cell-surface adhesins in Gram-positive bacteria. Thus, they play critical roles in virulence, infection and colonization by pathogens. Sortases have been classified into four types based on their primary sequence and the target-protein motifs that they recognize. All Gram-positive bacteria express a class A housekeeping sortase (SrtA). Sortase A from Streptococcus pneumoniae (NP_358691) has been crystallized in two crystal forms. Diamond-shaped crystals of ÁN 59 SrtA diffracted to 4.0 Å resolution and belonged to a tetragonal system with unit-cell parameters a = b = 122. ) with $56% solvent content suggested the presence of four molecules in the asymmetric unit for ÁN 81 SrtA. Also, a multi-copy search using a monomer as a probe in the molecular-replacement method resulted in the successful location of four sortase molecules in the asymmetric unit, with statistics R = 41.61, R free = 46.44, correlation coefficient (CC) = 64.31, CC free = 57.67.

We propose the notion of quantum coherence for superpositions over states which are not necessarily mutually distinguishable. This anticipatedly leads to a resource theory of non-orthogonal coherence. We characterize free states and free operations in this theory, and connect the latter with free operations in the resource theory of quantum coherence for distinguishable bases. We show that the concept of non-orthogonal coherence naturally furnishes us with a wave-particle duality in quantum double-slit experiments where the channels beyond the slits are leaky between them. Furthermore, we demonstrate existence of a unique maximally coherent qubit state corresponding to any given purity. In addition, and in contradistinction with the case of distinguishable bases, there appears a non-trivial minimally coherent qubit state for a given purity. We also study the behavior of quantum coherence for some typical configurations of non-orthogonal bases which have no analogs for orthogonal bases. We further investigate the problem of determining the energy cost of creating non-orthogonal coherence, and find that it scales linearly with the non-orthogonal coherence created.